ABSTRACT
BACKGROUND: Endometrial cancer is one of the most commonly diagnosed gynecological cancers worldwide, and early-stage high-risk endometrial cancer has a poor prognosis. Adjuvant treatments after surgery, such as chemotherapy and radiotherapy, have been widely used in clinical practice to improve patient survival. Medroxyprogesterone acetate is a synthetic progestogen that has been reported to have potential anticancer effects in endometrial cancer. However, its efficacy, safety, and long-term prognostic benefits as an adjuvant treatment for endometrial cancer remain controversial. Therefore, this study aimed to observe the efficacy and prognostic impact of adjuvant medroxyprogesterone acetate treatment in patients with early-stage high-risk endometrial cancer and evaluate its safety. AIM: To observe the efficacy and prognosis of adjuvant treatment of endometrial cancer with medroxyprogesterone acetate and to evaluate its safety. METHODS: We collected the clinical data of 200 patients with early-stage high-risk endometrial cancer who were admitted to the Department of Obstetrics and Gynecology of our hospital from January 2018 to December 2022. The control group (100 patients) underwent conventional surgical treatment, and the study group (100 patients) was administered adjuvant medroxyprogesterone acetate tablets on top of the control group. The Kaplan-Meier curve analysis and log-rank test were performed to determine the possible factors influencing the 5-year cumulative survival rate in the patients. The Cox regression analysis was performed to identify the factors influencing the survival prognosis of endometrial cancer. RESULTS: According to the Cox regression analysis, age [hazard ratio (HR) = 4.636, 95% confidence interval (95%CI): 1.411-15.237], pathological type (HR = 6.943, 95%CI: 2.299-20.977), molecular typing (HR = 5.789, 95%CI: 3.305-10.141), and myometrial infiltration (HR = 5.768, 95%CI: 1.898-17.520) were factors influencing the prognosis of patients with early-stage high-risk endometrial cancer. CONCLUSION: Age, pathological type, molecular typing, and myometrial infiltration were all relevant factors affecting the prognosis of early-stage high-risk endometrial cancer. The potential long-term prognostic benefit of adjuvant postoperative radiotherapy in patients with early-stage high-risk endometrial cancer is worthy of clinical consideration.
ABSTRACT
Heparinase I (Hep I), which specifically degrades heparin to oligosaccharide or unsaturated disaccharide, has an important role in the production of low molecular weight heparin (LMWH). However, low productivity and stability of heparinase I hinders its applications. Here, a novel heparinase I (BxHep-I) was cloned from Bacteroides xylanisolvens and overexpressed in soluble form in Escherichia coli. The expression conditions of BxHep-I were optimized for an activity of 7144 U/L. BxHep-I had a specific activity of 57.6 U/mg at the optimal temperature and pH of 30 °C and pH 7.5, with the Km and Vmax of 0.79 mg/mL and 124.58 U/mg, respectively. BxHep-I catalytic activity could be enhanced by Ca2+ and Mg2+, while strongly inhibited by Zn2+ and Co2+. Purified BxHep-I displayed an outstanding thermostability with half-lives of 597 and 158 min at 30 and 37 °C, respectively, which are the highest half-lives ever reported for heparinases I. After storage at 4 °C for one week, BxHep-I retained 73% of its initial activity. Molecular docking revealed that the amino acids Asn25, Gln27, Arg88, Lys116, His156, Arg161, Gln228, Tyr356, Lys358, and Tyr362 form 13 hydrogen bonds with the substrate heparin disaccharides in the substrate binding domain and are mainly involved in the substrate binding of BxHep-I. These results suggest that the BxHep-I with high stability could be a candidate catalyst for the industrial production of LMWH.
ABSTRACT
Heparinase I (EC 4.2.2.7), is an enzyme that cleaves heparin, showing great potential for eco-friendly production of low molecular weight heparin (LMWH). However, owing to its poor catalytic activity and thermal stability, the industrial application of heparinase I has been severely hindered. To improve the catalytic activity, we proposed to engineer both the substrate and Ca2+ binding domains of heparinase I. Several heparinases I from different organisms were selected for multiple sequence alignment and molecular docking to screen the key residues in the binding domain. Nine single-point mutations were selected to enhance the catalytic activity of heparinase I. Among them, T250D was the most highly active one, whereas mutations around Ca2+ binding domain yielded two active mutants. Mutant D152S/R244K/T250D with significantly increased catalytic activity was obtained by combined mutation. The catalytic efficiency of the mutant was 118,875.8 min-1·µM-1, which was improved 5.26 times. Molecular modeling revealed that the improved activity and stability of the mutants were probably attributed to the formation of new hydrogen bonds. The highly active mutant had great potential applications in industry and the strategy could be used to improve the performance of other enzymes.
HighlightsImproved catalytic activity of heparinase I by engineering the binding domains of substrate and Ca2+.The mutant D152S/R244K/T250D showed the highest catalytic performance.The increased hydrogen bonds attribute to the increased activity.
