ACAT1-mediated METTL3 acetylation inhibits cell migration and invasion in triple negative breast cancer.

Triple-negative breast cancer (TNBC) is a heterogeneous and aggressive disease with poor prognosis. Acetylation modifications affect a great number of biological processes of malignant tumors. The current study aims at revealing the role of acetylation-related mechanism in TNBC progression. Methyltransferase like-3 (METTL3) was found to be downregulated in TNBC cells via quantitative polymerase chain reaction (qPCR) and western blot analyses. Co-Immunoprecipitation (Co-IP) and GST pulldown assays revealed the interaction between acetyl-CoA acetyltransferase 1 (ACAT1) and METTL3. Through further immunoprecipitation (IP) assay, we determined that ACAT1 stabilizes METTL3 protein via inhibiting the degradation of ubiquitin-proteasome. Functionally, ACAT1 inhibits TNBC cell migration and invasion. Moreover, nuclear receptor subfamily 2 group F member 6 (NR2F6) regulates ACAT1 expression at transcriptional level. Finally, we demonstrated that NR2F6/ACAT/METTL3 axis suppresses the migration and invasion of TNBC cells via METTL3. In conclusion, NR2F6 transcriptionally activates ACAT1 and promotes the suppressive effects of ACAT1-mediated METTL3 acetylation on TNBC cell migration and invasion.

Risk factors of recurrent thyroid nodules after radiofrequency ablation.

Objective: To investigate the risk factors of thyroid nodule recurrence after radiofrequency ablation (RFA). METHODS The medical record information of 120 patients with thyroid nodules admitted to our hospital from June 2019 to April 2022 was retrospectively analysed. All participants received RFA treatment. According to the results of the postoperative thyroid ultrasound examination (USG), the patients were divided into the recurrence group (R, N=16) and the non-recurrence group (NR, N=104). Binary logistic regression analysis was performed to identify the independent risk factors of thyroid nodule recurrence after RFA. The receiver operating characteristic (ROC) curve was used to analyse the value of the forecast of each independent factor and combined model for thyroid nodule recurrence after RFA. Results: During the follow-up period, 16 patients recurred, and the recurrence rate was 13.33%. Univariate regression analysis showed that whether the nodules are solitary (WNS), nodule diameter (ND), the degree of risk of nodular location (DRN), recurrent laryngeal nerve (RLN) injury were associated with thyroid nodule recurrence after RFA (P<0.05). Binary logistic regression analysis showed that WNS, ND, DRN and RLN injury were independent risk factors for the recurrence of thyroid nodules after RFA (P<0.05). ROC analysis of independent factors and combined model showed that solitary nodules, nodule diameter and nodule location risk degree had diagnostic value, while RLN injury had no predictive value. The combined model is more predictive than the independent factors. Conclusions: The risk factors of recurrent thyroid nodules after radiofrequency ablation are related to WNS, ND, DRN and so on, which should be paid attention to and preventive measures should be taken.

Decellularization of porcine skeletal muscle extracellular matrix for the formulation of a matrix hydrogel: a preliminary study.

Extracellular matrix (ECM) hydrogels are used as scaffolds to facilitate the repair and reconstruction of tissues. This study aimed to optimize the decellularization process of porcine skeletal muscle ECM and to formulate a matrix hydrogel scaffold. Five multi-step methods (methods A-E) were used to generate acellular ECM from porcine skeletal muscle [rinsing in SDS, trypsin, ethylenediaminetetraacetic acid (EDTA), Triton X-100 and/or sodium deoxycholate at 4-37°C]. The resulting ECM was evaluated using haematoxylin and eosin, 4-6-diamidino-2-phenylindole (DAPI) staining, and DNA quantification. Acellular matrix was dissolved in pepsin and gelled at 37°C. Hydrogel response to temperature was observed in vivo and in vitro. ECM components were assessed by Masson, Sirius red, and alcian blue staining, and total protein content. Acellular porcine skeletal muscle exhibited a uniform translucent white appearance. No intact nuclear residue was detected by haematoxylin and eosin staining, while DAPI staining showed a few nuclei in the matrixes produced by methods B, C, and D. Method A generated a gel that was too thin for gelation. However, the matrix obtained by rinsing in 0.2% trypsin/0.1% EDTA, 0.5% Triton X-100, and 1% Triton X-100/0.2% sodium deoxycholate was nuclei-free and produced a viscous solution that formed a structurally stable white jelly-like hydrogel. The residual DNA content of this solution was 49.37 ± 0.72 ng/mg, significantly less than in fresh skeletal muscle, and decreased to 19.22 ± 0.85 ng/mg after gelation (P < 0.05). The acellular matrix was rich in collagen and glycosaminoglycan, with a total protein concentration of 64.8 ± 6.9%. An acellular ECM hydrogel from porcine skeletal muscle was efficiently produced.

[Application and research progress of bio-derived hydrogels in tissue engineering].

OBJECTIVE: To review the properties of bio-derived hydrogels and their application and research progress in tissue engineering. METHODS: The literature concerning the biol-derived hydrogels was extensively reviewed and analyzed. RESULTS: Bio-derived hydrogels can be divided into single-component hydro gels (collagen, hyaluronic acid, chitosan, alginate, silk fibroin, etc.) and multi-component hydrogels [Matrigel, the extract of extracellular matrix (ECM), and decellularized ECM]. They have favorable biocompatibility and bioactivity because they are mostly extracted from the ECM of biological tissue. Among them, hydrogels derived from decellularized ECM, whose composition and structure are more in line with the requirements of bionics, have incomparable advantages and prospects. This kind of scaffold is the closest to the natural environment of the cell growth. CONCLUSION: Bio-derived hydrogels have been widely used in tissue engineering research. Although there still exist many problems, such as the poor mechanical properties, rapid degradation, the immunogenicity or safety, vascularization, sterilization methods, and so on, with the deep-going study of optimization mechanism, desirable bioderived hydrogels could be obtained, and thus be applied to clinical application.

[High risk factors of the third level of lymphatic metastasis in breast cancer patients received radical/modified mastectomy: an analysis of 746 cases].

OBJECTIVE: To study the high risk factors of the third level of lymphatic metastasis in breast cancer patients to guide clinical practice. METHODS: The clinical data of 746 breast cancer patients (all female, aged from 33 to 80 years with a median of 46 years) received radical or modified mastectomy between 2001 and 2011 was analyzed retrospectively. Eleven individual variables were selected to investigate high risk factors of the third level of lymphatic metastasis in different conditions. RESULTS: Axillary nodes metastasis status (OR = 4.541, 95%CI:3.569-5.776), tumor site (OR = 1.437, 95%CI:1.029-2.007), external nodes involved (OR = 3.809, 95%CI:1.683-8.618) and estrogen receptor (OR = 0.740, 95%CI:0.569-0.964) were high risk factors of the third level of lymphatic metastasis. Further analysis found that it is prone to happen a metastasis, especially when the tumor with a size over 5 cm and located at the lateral quadrant. Negative estrogen receptor was a risk factor of the third level lymphatic metastasis along with the tumor stage. CONCLUSION: For preoperative tumor biopsy shows Negative estrogen receptor of tumor stage T3 and over stage T3 when considering suspicious lymph node metastasis or external tissues metastasis intraoperatively should take in account into third level axillary lymph node dissection actively.

[Preparation and characterization of acellular adipose tissue matrix].

OBJECTIVE: To prepare human acellular adipose tissue matrix and to evaluate the cellular compatibility so as to explore a suitable bio-derived scaffold for adipose tissue engineering. METHODS: The adipose tissue was harvested from abdominal skin graft of breast cancer patients undergoing radical mastectomy or modified radical mastectomy, and then was treated with a series of decellularization processes including repeated freeze-thaw, enzyme digestion, and organic solvent extraction. The matrix was examined by histology, immunohistochemistry, DAPI fluorescence staining, and scanning electron microscopy to observe the the removal of cells and to analyze its composition of collagen type IV, laminin, and fibronectin, and microstructure. The 3rd passage human adipose-derived stem cells (hADSCs) were co-cultured with acellular adipose tissue matrix and different concentrations of extracted liquid (100%, 75%, 50%, and 25%). The cytotoxic effects of the matrix were tested by MTT. The biocompatibility of the matrix was detected by live/dead staining and scanning electron microscopy observation. RESULTS: The acellular adipose tissue matrix basically maintains intrinsical morphology. The matrix after acellular treatment consisted of extracellular matrix without any cell components, but there were abundant collagen type I; neither DNA nor lipid residual was detected. Moreover, the collagen was the main component of the matrix which was rich in laminin and fibronectin. At 1, 3, and 5 days after co-cultured with hADSCs, the cytotoxic effect of matrix was grade 0-1. The matrix displayed good cell compatibility and proliferation. CONCLUSION: The acellular adipose tissue matrix prepared by repeated freeze-thaw, enzyme digestion, and organic solvent extraction method remains abundant extracellular matrix and has good cellular compatibility, so it is expected to be an ideal bio-derived scaffold for adipose tissue engineering.