BACKGROUND: Mutations in the structural domain of the epidermal growth factor receptor (EGFR) kinase represent a critical pathogenetic factor in non-small cell lung cancer (NSCLC). Small-molecule EGFR-tyrosine kinase inhibitors (TKIs) serve as first-line therapeutic agents for the treatment of EGFR-mutated NSCLC. But the resistance mutations of EGFR restrict the clinical application of EGFR-TKIs. In this study, we constructed a clinically relevant PC-9 EGFRD19/T790M/C797S cellular model featuring the mutation type within the EGFRD19/T790M/C797S. This model aims to investigate the inhibitory effects of small-molecule EGFR-TKIs and to provide a cellular platform for developing a new generation of innovative drugs that target resistance associated with EGFR mutations. METHODS: Clustered regularly interspaced short palindromic repeats/CRISPR-associated nuclease 9 (CRISPR/Cas9) technology was employed to knock in the EGFRT790M/C797S mutant fragment into NSCLC PC-9 cells, originally harboring the EGFRD19 mutation, to generate the PC-9 EGFRD19/T790M/C797S cell model. This model, with the EGFRD19/T790M/C797S mutant, was used to investigate the inhibitory effects of EGFR-TKIs on cell proliferation through MTS assay. Additionally, Western blot analysis was conducted to assess the regulation of EGFR protein expression and the phosphorylation levels of downstream signaling molecules, including protein kinase B (AKT) and mitogen-activated protein kinase (MAPK). RESULTS: PC-9 EGFRD19/T790M/C797S cells, with the EGFRD19/T790M/C797S mutation, were successfully generated using CRISPR/Cas9 technology. In terms of proliferation inhibition, the marketed first-, second-, and third-generation EGFR-TKIs that were ineffective against the EGFRD19/T790M/C797S mutation showed weak proliferation inhibitory activity against this cell line, and the proliferation inhibition (half maximal inhibitory concentration, IC50)>1000 nmol/L; in contrast, the fourth-generation EGFR-TKIs in development, which have better efficacy against the EGFRD19/T790M/C797S mutation, showed strong proliferation inhibition in this cell model. On mechanistic validation, the first-, second-, and third-generation EGFR-TKIs had weak inhibitory activity on the phosphorylation of EGFR and the downstream AKT/MAPK signaling pathway in this cell line, whereas the fourth generation of EGFR-TKIs under development significantly inhibited the phosphorylation of EGFR and the downstream AKT/MAPK signaling pathway in this cell line. CONCLUSIONS Using CRISPR/Cas9 technology, the EGFRT790M/C797S mutant fragment was successfully knocked into PC-9 cells to create cell lines harboring the EGFRD19/T790M/C797S mutation. The study demonstrated that the EGFR-TKIs showed different sensitivities to whether the EGFRD19/T790M/C797S mutation was effective or not and different inhibitory effects on the phosphorylation of EGFR and downstream pathways, which demonstrated that this cell line depended on the activation of the EGFRD19/T790M/C797S mutation and EGFR/AKT/MAPK signaling pathway for proliferation. This study provides a clinically relevant cellular evaluation and mechanism validation system for the development of a new generation of innovative drugs targeting EGFR mutation resistance.
ErbB Receptors/metabolism* ; Carcinoma, Non-Small-Cell Lung/metabolism* ; Humans ; Drug Resistance, Neoplasm/genetics* ; Lung Neoplasms/metabolism* ; Protein Kinase Inhibitors/pharmacology* ; Mutation ; Cell Line, Tumor ; Cell Proliferation/drug effects* ; Antineoplastic Agents/pharmacology*

The global COVID-19 coronavirus pandemic has infected over 109 million people, leading to over 2 million deaths up to date and still lacking of effective drugs for patient treatment. Here, we screened about 1.8 million small molecules against the main protease (M^pro) and papain like protease (PL^pro), two major proteases in severe acute respiratory syndrome-coronavirus 2 genome, and identified 1851M^pro inhibitors and 205 PL^pro inhibitors with low nmol/l activity of the best hits. Among these inhibitors, eight small molecules showed dual inhibition effects on both M^pro and PL^pro, exhibiting potential as better candidates for COVID-19 treatment. The best inhibitors of each protease were tested in antiviral assay, with over 40% of M^pro inhibitors and over 20% of PL^pro inhibitors showing high potency in viral inhibition with low cytotoxicity. The X-ray crystal structure of SARS-CoV-2 M^pro in complex with its potent inhibitor 4a was determined at 1.8 Å resolution. Together with docking assays, our results provide a comprehensive resource for future research on anti-SARS-CoV-2 drug development.
Humans ; Antiviral Agents/chemistry* ; COVID-19 ; COVID-19 Drug Treatment ; High-Throughput Screening Assays ; Molecular Docking Simulation ; Protease Inhibitors/chemistry* ; SARS-CoV-2/enzymology* ; Viral Nonstructural Proteins

Objective:To investigate the clinicopathological characteristics and prognostic factors of patients with esophageal cancer.Methods:The retrospective case-control study was conducted. The clinicopathological data of 447 patients with esophageal cancer who were admitted to the Fourth Hospital of Hebei Medical University from January 1, 2017 to December 31, 2020 were collected. There were 312 males and 135 females, aged 60(range, 37?82)years. Observation indica-tors: (1) clinicopathological characteristics; (2) treatment; (3) follow-up; (4) analysis of prognostic factors for esophageal cancer. Follow-up using telephone interview or outpatient examination was conducted to detect survival of patients up to December 2021. The total survival time was from the surgery date to death or the last follow-up. Patients with duration of follow-up more than 2 years were included for survival and prognostic analysis. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M(range). Count data were represented as absolute numbers. Kaplan-Meier method was used to draw survival curves and calculate survival rates. Log-Rank test was used for survival analysis. Univariate analysis was conducted using the Log-rank test. Multivariate analysis was conducted using the COX hazard regression model. Results:(1) Clinicopathological characteristics. Of the 447 patients, 69.80%(312/447) were males and 30.20%(135/447) were females, and there were 3, 18, 101, 229, 93, 3 cases aged 30?39 years, 40?49 years, 50?59 years, 60?69 years, 70?79 years, 80?89 years, respectively. About the pathological type, there were 424 cases with squamous carcinoma, 11 cases with small cell carcinoma, 4 cases with adenosquamous carcinoma, 3 cases with sarco-matoid carcinoma, 2 cases with adenocarcinoma, 1 case with neuroendocrine carcinoma, 1 case with undifferentiated carcinoma, and 1 case with adenoid cystic carcinoma. There were 2 cases with tumor located at cervicothoracic segment, 49 cases with tumor located at upper thoracic segment, 273 cases with tumor located at mid-thoracic segment, and 123 cases with tumor located at lower thoracic segment. There were 6, 24, 74, 59, 192, 80, 12 cases in stage pT0, pT1a, pT1b, pT2, pT3, pT4a, pT4b of pathological T staging, respectively. There were 207, 63, 142, 28, 7 cases in stage pN0, pN1, pN2, pN3, pN4 of pathological N staging by Japan Esophagus Society (JES), respectively. There were 207, 128, 76, 36 cases in stage pN0, pN1, pN2, pN3 of pathological N staging by Union for International Cancer Control (UICC), respectively. About TNM staging, there were 25, 53, 127, 174, 68 cases in stage 0, Ⅰ, Ⅱ, Ⅲ, Ⅳa of JES staging, and 16, 9, 53, 35, 108, 96, 45, 85 cases in stage 0, Ⅰa, Ⅰb,Ⅱa, Ⅱb, Ⅲa, Ⅲb, Ⅲc of UICC staging, respectively. (2) Treatment. Of the 447 patients, 63 cases underwent neoadjuvant therapy(12 cases combined with immunotherapy), 384 cases underwent no neoadjuvant therapy. There were 347, 97, 2, 1 cases with surgical approach as right thoracic approach, left thoracotomy approach, cervical abdominal approach, left thoracoabdominal approach, respectively. There were 316, 5, 126 cases with surgical platform as totally endoscopic esophagec-tomy, Hybrid surgery, open surgery, respectively. There were 350 and 97 cases with digestive recons-truction as posterior mediastinal approach and intrathoracic approach, respectively. Surgical margin as R 0, R 1, R 2 resection was detected in 323, 116, 8 cases, respectively. Six of 447 patients died during the hospital stay. (3) Follow-up. All the 447 patients were followed up for 25(range, 2?48)months, including 233 cases with the follow-up more than 2 years. The median survival time of 233 patients was unreached, and the postoperative 2-year survival rate was 76.8%. (4) Analysis of prognostic factors for esophageal cancer. Results of univariate analysis showed that gender, neoadjuvant therapy, surgical margin, pT staging, pN staging by JES, pN staging by UICC, TNM staging by JES, TNM staging by UICC were related factors influencing prognosis of 233 patients with esophageal cancer ( χ2=6.62, 17.81, 32.95, 37.93, 27.06, 35.56, 45.24, 37.84, P<0.05). Results of multivariate analysis showed that gender, surgical margin, TNM staging by JES were independent factors influencing prognosis of 233 patients with esophageal cancer ( hazard ratio=0.48, 1.94, 1.46, 95% confidence intervals as 0.25?0.91, 1.07?3.52, 1.16?1.84, P<0.05). Conclusions:The incidence of esophageal cancer is relatively high in males, with the onset age mainly distribute in 60?69 years and the mainly pathological type as squamous carcinoma. Patients with esophageal cancer have advanced tumor staging, low proportion of neoadjuvant therapy, high R 0 resection rate of surgical treatment. Gender, surgical margin, TNM staging by JES are independent factors influencing prognosis of patients with esophageal cancer.

BACKGROUND: Video assisted thoracic surgery (VATS) is the main surgical method for lung cancer. The aim of this study was to analyze the reasons for conversion to thoracotomy in 83 cases among 1,350 consecutive cases who underwent video-assisted thoracic surgery (VATS) lobectomy by a single surgical team, in order to achieve a deeper understanding of the rules and the opportunity for conversion to thoracotomy in VATS lobectomy under normal conditions. METHODS: The clinical data of 1,350 patients who underwent VATS lobectomy between September 21, 2009 and June 1, 2020, by a single surgical team in the Fifth Department of Thoracic Surgery of the Fourth Hospital of Hebei Medical University were retrospectively analyzed. There were 773 males and 577 females, aged 8-87 years, with a median age of 61.3 years, including 83 cases of benign diseases, 38 cases of lung metastases, and 1,229 cases of primary lung cancer. The cases with stage I, II and IIIa were 676, 323 and 230, respectively. The cases of left upper, left lower, right upper, right middle, right lower, right middle and upper and right middle and lower lobectomy were 301 (22.30%), 231 (17.11%), 378 (28.00%), 119 (8.81%), 262 (19.41%), 16 (1.19%) and 43 (3.19%), respectively. RESULTS: In the cohort of 1,350 consecutive patients with VATS lobectomy, 83 patients (6.15%) were converted to thoracotomy for different reasons. The conversion rate of benign lesions was significantly higher than that of malignant tumors (P<0.05). The conversion rate in stage IIIa was significantly higher than that in stage I and II (P<0.05). The conversion rate of combined lobectomy was significantly higher than that of single lobectomy (P=0.001). The conversion rate of left upper lobectomy was significantly higher than that of other single lobectomy (P<0.001). The conversion rate of right middle lobectomy was significantly lower than that of other single lobectomy (P=0.049). The main reasons for conversion were vascular injury (38.55%), lymph node interference (26.51%) and dense adhesion in thoracic cavity (16.87%). In the conversion group, the total operation time was (236.99±66.50) min and the total blood loss was (395.85±306.38) mL. The operation time in patients converted to thoracotomy due to lymph node interference was (322.50±22.68) min, which was significantly longer than that in the other groups (P<0.05). The intraoperative blood loss in patients converted to thoracotomy due to vascular injury was (560.94±361.84) mL, which was significantly higher than that in the other groups (P<0.05). With the increase in surgical experience, the number of vascular injuries gradually decreased at the early stage, mid-stage and late stage (P=0.045). CONCLUSIONS In VATS lobectomy, benign lung lesions and more advanced malignant tumors led to more surgical difficulties and higher conversion rate. The conversion rate was different in different lobectomy sites, with the highest in left upper lobectomy, and the lowest in right middle lobectomy. Vascular injury, lymph node interference and dense adhesion were the main reasons for conversion to thoracotomy, which led to prolonged operation time and increased blood loss. With the increasing number of surgical cases, the rate of conversion to thoracotomy in VATS lobectomy continues to decline, which may be mainly due to the more advanced treatment of pulmonary vessels.