Research Progress on hCNT3 Structure/Function and Nucleoside Anticancer Drugs.

Membrane protein human concentrative nucleoside transporter 3 (hCNT3) can not only transport extracellular nucleosides into the cell but also transport various nucleoside-derived anticancer drugs to the focus of infection for therapeutic effects. Typical nucleoside anticancer drugs, including fludarabine, cladabine, decitabine, and clofarabine, are recognized by hCNT3 and then delivered to the lesion site for their therapeutic effects. hCNT3 is highly conserved during the evolution from lower to higher vertebrates, which contains scaffold and transport domains in structure and delivers substrates by coupling with Na+ and H+ ions in function. In the process of substrate delivery, the transport domain rises from the lower side of transmembrane 9 (TM9) in the inward conformation to the upper side of the outward conformation, accompanied by the collaborative motion of TM7b/ TM4b and hairpin 1b (HP1b)/ HP2b. With the report of a series of three-dimensional structures of homologous CNTs, the structural characteristics and biological functions of hCNT3 have attracted increasing attention from pharmacists and biologists. Our research group has also recently designed an anticancer lead compound with high hCNT3 transport potential based on the structure of 5-fluorouracil. In this work, the sequence evolution, conservation, molecular structure, cationic chelation, substrate recognition, elevator motion pattern and nucleoside derivative drugs of hCNT3 were reviewed, and the differences in hCNT3 transport mode and nucleoside anticancer drug modification were summarized, aiming to provide theoretical guidance for the subsequent molecular design of novel anticancer drugs targeting hCNT3.

Prognostic Factors and Outcomes in Elderly Esophagectomy Patients with Esophageal Cancer.

BACKGROUND: Choosing the appropriate treatment for elderly patients with esophageal cancer remains a contentious issue. While surgery is still a valid option, we aimed to identify predictors and outcomes in elderly esophagectomy patients with esophageal cancer. PATIENTS AND METHODS: We analyzed characteristics, surgical outcomes, survival rates, cause-specific mortality, and recurrence in 120 patients with stage I-IV esophageal cancer. Univariate and multivariate analyses were used to identify risk factors for event-free survival (EFS) and overall survival (OS). RESULTS: The median follow-up period was 31 months, with 5-year overall survival (OS) and event-free survival (EFS) rates standing at 45.2% and 41.5%, respectively. Notably, lower body mass index (BMI ≤ 22 kg/m2) and reduced preoperative albumin levels (pre-ALB < 40 g/L) led to a significant decrease in OS rates. Postoperative pulmonary complications resulted in higher in-hospital and 90-day mortality rates. After about 31 months post-surgery, the rate of cancer-specific deaths stabilized. The most common sites for distant metastasis were the lungs, supraclavicular lymph nodes, liver, and bone. The study identified lower BMI, lower pre-ALB levels, and postoperative pulmonary complications as independent risk factors for poorer EFS and OS outcomes. CONCLUSIONS: Esophagectomy remains a safe and feasible treatment for elderly patients, though the prevention of postoperative pulmonary infection is crucial. Factors such as lower BMI, lower pre-ALB levels, advanced tumor stage, postoperative pulmonary complications, and certain treatment modalities significantly influence the outcomes in elderly esophagectomy patients. These findings provide critical insights into the characteristics and outcomes of this patient population.

High-dose chemotherapy sensitizes locally advanced esophageal squamous cell carcinoma to PD-1 blockade for a higher pathological complete response rate and survival.

BACKGROUND: PD-1 inhibitor and chemotherapy demonstrated durable antitumor activity with a manageable safety profile as the first-line treatment in patients with advanced esophageal squamous cell carcinoma (ESCC). The present study aimed to evaluate the efficacy of PD-1 inhibitors plus different dose intensity neoadjuvant chemotherapy in the treatment of locally advanced ESCC. METHODS: Patients with locally advanced but resectable thoracic ESCC, staged as T3 or T4a, N0-3, and M0 or M1 lymph node metastasis (confined to the supraclavicular lymph nodes), were enrolled in this study. The eligible patients received tislelizumab plus different dose intensity chemotherapy for a 21-day cycle with repeated 2-4 cycles before surgery. The primary endpoints are pathological complete response (pCR) and major pathological response (MPR), and the secondary endpoints are objective response rate (ORR), disease control rate (DCR), and disease-free survival (DFS). RESULTS: From November 2019 to February 2022, 122 cases received at least two cycles neoadjuvant chemoimmunotherapy and were evaluated by imaging examination. Subsequently, 99 patients underwent surgery and were evaluated by pathological evaluation. According to chemotherapy dose intensity, the patients were divided into three cohorts: cohort 1 (<80% dose intensity), cohort 2 (80-90% dose intensity), cohort 3 (90-100% dose intensity). All surgery patients underwent minimally invasive esophagectomy (MIE). The average pCR was identified in 22.22%; 16% had pCR in cohort 1, 17.65% had pCR in cohort 2, and 30.00% had pCR in cohort 3. MPR was observed in 9 (36.00%) patients in cohort 1, 18 (52.94%) patients in cohort 2, 22 (55.00%) patients in cohort 3. In univariable and multivariable analysis, dose intensity was significantly associated with MPR (p = 0.048) in patients who underwent esophagectomy. For surviving patients, the median follow-up was 13.76 months after esophagectomy. Compared to cohort 1, cohorts 2 and 3 had better DFS (p = 0.056). In addition, the prognosis of patients with MPR was better than that of patients without MPR (p = 0.014). CONCLUSIONS: The robust antitumor activity of neoadjuvant chemoimmunotherapy for locally advanced but resectable thoracic ESCC was confirmed. More than 80% of chemotherapy dose intensity combined with immunotherapy resulted in a high pCR rate and prolonged DFS.

Purse-indigitation mechanical anastomosis vs. traditional mechanical anastomosis undergoing McKeown esophagectomy: a retrospective comparative cohort study.

Background: Postoperative anastomosis-related complication rates remain high in patients undergoing McKeown esophagectomy with cervical anastomosis, and the optimal anastomotic technique remains under debate. We describe a new method of anastomosis, referred to as purse-indigitation mechanical anastomosis (PIMA) by reinforcing esophagogastric anastomosis, which can be performed after minimally invasive surgery. This study was designed to compare its feasibility, efficacy, and safety with those of traditional mechanical anastomosis (TMA). Methods: Between September 2020 and January 2022, 264 patients undergoing McKeown esophagectomy at a single center were included. Demographic data, including patient age, sex, diagnosis, neoadjuvant chemotherapy/radiation therapy in cases of malignancy, comorbidities, and operation time, anastomotic time, estimated blood loss, post­operative complications were collected. Their medical records were retrospectively reviewed, analyzed and compared between the PIMA and TMA cohorts. Results: The baseline comparability of the PIMA and TMA before the comparisons is no statistical difference. Univariable analysis revealed significantly decreased anastomotic leak rate with PIMA compared to TMA (4.10% vs. 11.59%, P=0.04). No significant difference was demonstrated in total operation time, estimated blood loss, postoperative hospital stay, or pulmonary complications between PIMA and TMA (243.94±21.98 vs. 238.70±28.45 min; 201.10±67.83 vs. 197.39±65.13 mL; 8.83±2.77 vs. 9.35±3.78 days; 8.21% vs. 11.59%; all P>0.05). The incidence of postoperative pulmonary complications (3.44% vs. 50%) was significantly associated with an increased rate of anastomotic leak [odds ratio (OR): 15.50; 95% confidence interval (CI): 4.81-43.71; P<0.01]. Conclusions: PIMA is feasible, safe to perform, and demonstrated a leak rate less than half that of TMA in this study. PIMA may represent a superior alternative to standard esophagogastric cervical anastomosis techniques. Larger sample size and long-term survival are required to fully evaluate PIMA.

The analyses of relationships among nucleotide, synonymous codon and amino acid usages for E2 gene of bovine viral diarrhea virus.

In this study, the systemic analyses of nucleotide, codon and amino acid usages for E2 gene of bovine viral diarrhea virus (BVDV) were carried out for estimating its genetic features. The nucleotide usage pattern at the first codon position was strongly influenced by the overall nucleotide composition, while the nucleotide usage patterns at the second and third codon positions seemed to have little link to the overall nucleotide composition. The result indicated that the mutation pressure from nucleotide composition constraint was not the single evolutionary force for genetic features of BVDV E2 gene. Just 18 out of 59 synonymous codons were similar with synonymous codon usage patterns for E2 gene between BVDV1 and BVDV2, while all synonymous codons which contain CpG dinucleotides were selected at the low level by E2 gene, suggesting that this gene suppressed the usages of codons containing CpG dinucleotides to regulate E2 gene replicate and transcript efficiently and avoid immune response from infected hosts. Amino acid usage patterns of E2 protein were generally different between BVDV1 and BVDV2. The patterns of synonymous codon and amino acid usages for E2 gene might be caused by the equilibrium of evolutionary forces from virus and host. Our work gave new investigations into the role of host origin in the formations of synonymous codon/amino acid usages and the evolutionary trend of BVDV E2 gene. The genetic characteristics that codon/amino acid usages of E2 gene adapted to the internal environment of individual animals might assist in understanding the changes of genetics and antigenicity for newly emerging BVDV.