Effect of angiotensin receptor-neprilysin inhibitor on atrial electrical instability in atrial fibrillation.

Background and objective: Around 33.5 million patients suffered from atrial fibrillation (AF), causing complications and increasing mortality and disability rate. Upstream treatment for AF is getting more popular in clinical practice in recent years. The angiotensin receptor-neprilysin inhibitor (ARNI) is one of the potential treatment options. Our study aimed to investigate the effect of ARNI on atrial electrical instability and structural remodeling in AF. Methods: Our research consisted of two parts - a retrospective real-world clinical study and an animal experiment on calmness to verify the retrospective founding. In the retrospective study, we reviewed all patients (n = 110) who had undergone the first AF ablation from 1 August 2018 to 1 March 2022. Patients with ARNI (n = 36) or angiotensin II receptor antagonist (ARB) (n = 35) treatment were enrolled. Their clinical data, ultrasound cardiogram (UCG) and Holter parameters were collected before radiofrequency catheter ablation (RFCA) as baseline and at 24-week follow-up. Univariate and multivariate logistic regression analysis were performed. In the animal experiment, we established an AF model (n = 18) on canines by rapid atrial pacing. After the successful procedure of pacing, all the 15 alive beagles were equally and randomly assigned to three groups (n = 5 each): Control group, ARB group, and ARNI group. UCG was performed before the pacing as baseline. Physiological biopsy, UCG, and electrophysiological study (EPS) were performed at 8-week. Results: Clinical data showed that the atrial arrhythmia rate at 24-week was significantly lower in ARNI group compared to ARB group (P < 0.01), and ARNI was independently associated with a lower atrial arrhythmia rate (P < 0.05) at 24-week in multivariate regression logistic analysis. In the animal experiment, ARNI group had a higher atrial electrical stability score and a shorter AF duration in the EPS compared to Control and ARB group (P < 0.05). In the left atrium voltage mapping, ARNI group showed less low voltage and disordered zone compared to Control and ARB group. Compared to Control group, right atrium diameter (RAD), left ventricle end-diastolic volume index (LVEDVI), E/A, and E/E' were lower in ARNI group (P < 0.05) at the 8-weeks follow-up, while left atrium ejection fraction (LAEF) and left ventricle ejection fraction (LVEF) were higher (P < 0.01). Compared to ARB group, LVEF was higher in ARNI group at the 8-week follow-up (P < 0.05). ARB and ARNI group had a lower ratio of fibrotic lesions in the left atrium tissues compared to Control group (P < 0.01), but no difference was found between the ARB and the ARNI group. Conclusion: ARNI could reduce atrial electrical instability in AF in comparison with ARB in both retrospective study and animal experiment.

A preliminary study of the effect of ECRG4 overexpression on the proliferation and apoptosis of human laryngeal cancer cells and the underlying mechanisms.

Human esophageal cancer­related gene 4 (ECRG4) is a potential tumor suppressor gene isolated from human esophageal epithelial cells. Studies have shown that ECRG4 effectively inhibits the proliferation of tumor cells and induces apoptosis. However, the role of ECRG4 in laryngeal cancer has not yet been clearly defined. In this study, a human laryngeal cancer cell line stably overexpressing ECRG4 was established. The effect of ECRG4 on the proliferation and apoptosis of laryngeal cancer cells and the associated mechanisms were investigated. The Hep­2 human laryngeal carcinoma cell line exhibited a low basal level of ECRG4 expression and was selected for the present study. The eukaryotic expression plasmid pcDNA3.1­ECRG4 was constructed and introduced into Hep­2 cells by transfection reagents. Western blot analysis, reverse transcription-quantitative polymerase chain reaction and immunofluorescence staining confirmed high­level expression of ECRG4. The 3­(4, 5­dimethylthiazol­2­yl)­2,5­diphenyltetrazolium bromide assay and colony formation assay showed that ECRG4 overexpression suppressed the proliferative capacity of laryngeal cancer cells in vitro. Cell cycle analysis showed that ECRG4 induced cell cycle arrest at the G0/G1 phase. Flow cytometric analysis and Hoechst staining demonstrated that overexpression of ECRG4 significantly induced apoptosis. Western blot analysis confirmed that Bcl­2­associated X protein, cleaved­caspase­3 and cleaved­poly (ADP­ribose) polymerase were upregulated in the apoptotic process, whereas B­cell lymphoma 2 was downregulated. In conclusion, overexpression of ECRG4 inhibited laryngeal cancer cell proliferation and induced cancer cell apoptosis. Therefore, ECRG4 exhibits potential as an effective target in gene therapy for laryngeal cancer.

[Short-term impact of modified blood-lipid reports on physicians' lipid lowering drug prescribing behavior and knowledge improvement on dyslipidemia].

OBJECTIVE: To compare the physicians' lipid lowering drug prescribing behavior and knowledge on dyslipidemia before and at 8 months after new-issued blood-lipid reports in our hospital. METHOD: Blood-lipid reports in our hospital is newly modified in that the classification of dyslipidemia and lipid-lowering guideline and target lipid level are listed on the back of lipid report besides the normal lipid value listed immediately after the measured lipid levels. Physicians' lipid lowering drug prescribing behavior and knowledge on dyslipidemia before and at 8 months after new-issued blood-lipid reports were examined in 143 doctors from various departments before and at 8 months after new-issued lipid reports. RESULTS: At 8 months after the new issued lipid reports, doctors' cognition rate about the guideline was significantly increased [83.9% (120/143) vs. 67.1% (96/143), P < 0.001] and the guideline was considered more helpful on daily practice [75.3% (58/77) vs. 55.8% (43/77), P = 0.005] compared to baseline. However, the prescription rate of dyslipidemia therapy did not change significantly (69.2% vs. 63.2%, P = 0.117) at 8 months after the new issued lipid reports. CONCLUSIONS: The modification of the blood-lipid reports improved doctors' knowledge on dyslipidemia and on the "Chinese guidelines on prevention and treatment of dyslipidemia in adults". However, the lipid lowering drug prescribing behavior remained unchanged at 8 months after the modification of the lipid reports. Further investigation is warranted to see if the lipid lowering drug prescribing behavior could be changed in the long-term.

Average-12.9 chromosome imbalances coupling with 15 differential expression genes possibly involved in the carcinogenesis, progression and metastasis of supraglottic laryngeal squamous cell cancer.

OBJECTIVE: With the objective of discovering novel putative chromosomal regions and special genes involved in the carcinogenesis, progression and metastasis of laryngeal squamous cell cancer (LSCC). METHODS: DNA copy profile of LSCC were obtained and analyzed by comparative genomic hybridization (CGH) and a computerized digital image analysis system. cDNA microarray of LSCC was performed and the profile was analyzed by Hierarchical clustering. RESULTS: CGH analysis showed average-12.9 gains and losses of chromosomes in LSCC. Relatively high frequencies of gains were found at 3q15-21 (14/18), 5p12-13 (11/18), 8q22-24 (6/18), 11q12-13 (8/18), 15q21-23 (7/18) and 18p11 (8/18), while those of losses at 1p13-21 (8/18), 3p21-23 (14/18), 5q21-22 (14/18), 9p12-pter (11/18) and 13q21-31 (8/18). Hierarchical clustering analysis showed that the differentially expressed genes were segregated into three groups. Three genes differentially expressed in process I (normal tissue to cancer) and process II (cancer to lymph node metastasis), and the Cy5/Cy3 ratios of twelve genes were either higher than 5.0 or lower than 0.2 in process I or process II. The fifteen special genes were first reported possibly to be the relationships with LSCC. In particular, 4 genes of them, which were cytochrome C oxidase Va, PPBP, EPHX2 and PON1, were first reported to correlate with tumorigenesis. SH3GL2, which was one of the 15 special genes, was located at one of the special chromosome regions, 9p12-pter. CONCLUSION: The important genes and special chromosomal aberrances might provide us a clue for further investigation of carcinogenesis, progression and metastasis in LSCC.

[Study on STK15 gene abnormality and centrosomal amplification in laryngeal carcinoma].

OBJECTIVE: To investigate STK15 gene abnormality and centrosomal amplification in laryngeal carcinoma. METHODS: STK15 gene mRNA expressional level was tested in 62 cases of laryngeal squamous cell carcinoma and laryngeal squamous cell carcinoma cell line Hep-2 by reverse transcription-polymerase chain reaction(RT-PCR); the mutation of STK15 gene exon 6 and exon 7 in the same tissues and cells was detected by PCR-single strand conformation polymorphism. Immunofluorescent antibodies were used to test centrosomal amplification in Hep-2 cell line as an example. RESULTS: STK15 gene overexpressed in 39 cases of laryngeal carcinoma (63%) and Hep-2 cell line. No mutation was found in exon 6 and exon 7 of STK15 gene in the above tissues and cells. Centrosomal amplification was apparent in Hep-2 cell line. The number of centrosome in a single cell changed from 1 to 7, and Hep-2 cells with amplified centrosomes (more than 2 in one cell) were 11%-23%. CONCLUSION: STK15 gene overexpression and centrosomal amplification were first found in human laryngeal squamous cell carcinoma, which indicated that STK15 gene overexpression leading to centrosomal amplification might occur in the early stage of human laryngeal carcinogenesis and be one of the key mechanisms for the occurrence of laryngeal carcinoma.

[Cloning and characterization of MTLC, a novel gene in 6q25].

OBJECTIVE: To identify and characterize laryngeal cancer related novel genes located on chromosome 6q25. METHODS: Electric hybridization was performed in human genome database using EST (expression sequence tag) as probe. Novel genes were deduced by software from positive DNA clones and their cDNAs were amplified by RT-PCR using primers designed according to the sequence of the putative genes. RESULTS: A novel gene was cloned successfully. The full length of this gene was about 21 kb. It contained two exons and produced a 1006 bp transcript coding a protein with 235 amino acid residues. It's 5'flanking sequence contained two binding sites of oncoprotein c-Myc, thus it was named MTLC (c-Myc target from laryngeal cancer cells). Homologous assay showed that MTLC exhibited little overall homology to known human proteins but it exhibited good overall homology to mouse MT-MC1 protein with an identity of 78%. The primary structure of MTLC protein contained a nuclear location signal motif, but it did not have other conserved domains. The results of subcellular location experiment showed that MTLC expressed in nuclei of human hepatocellular carcinoma cell line Bel7402 cells, while a wide distribution of MTLC in various tissues was demonstrated by Northern blotting. CONCLUSION: MTLC may play an important role as a target gene of c-Myc and as a transcription factor in keeping the normal physiological process of cells.

[Studies of the deletion and expression of cytokeratin 13 gene in laryngeal squamous cell carcinoma].

In order to investigate the role of Cytokeratin 13(CK13) gene in laryngeal carcinogenesis, we detected the deletion of CK13 gene through LOH analysis indirectly at DNA level using 5 STR primers within and near CK13 gene in 72 cases of laryngeal squamous cell carcinoma, then detected the differential expression between 16 cases of paired normal and cancerous tissue by Northern blot, and performed immunohistochemistry using well characterized monoclonal antibody against CK13 in squamous cell carcinoma of different stages. We found that all of the microsatellite loci exist LOH, and the LOH frequencies were 18.03%, 28.13%, 27.42%, 39.68% and 34.85% at D17S1964E, D17S2092, D17S791, D17S1665 and D17S808 respectively. The LOH+ cases accounted for 77.78% (56/72), and the frequencies of LOH were not related to the type of laryngeal carcinoma and the lymphoid metastasis; but significantly related to the differentiation, P < 0.05. CK13 gene is expressed significantly higher in 16 cases of normal tissues than in paired cancerous tissues, and the immunostain revealed that CK13 was expressed in normal laryngeal squamous cell or high differentiation stage, and its expression decreased or disappeared in poor ones, P < 0.01. CK13 gene might play an important role in the laryngeal carcinogenesis, acting as a novel tumor suppressor gene, and may be relevant to laryngeal squamous cell carcinoma diagnosis and prognosis. Further research will contribute to conform it.

[Study on the loss of heterozygosity and expression of transglutaminase 3 gene in laryngeal carcinoma].

OBJECTIVE: To investigate the role of transglutaminase 3 (TGM3) gene in laryngeal carcinogenesis. METHODS: The authors detected the deletion indirectly through loss of heterozygosity (LOH) analysis at DNA level using 4 STR primers within and near TGM3 gene in 72 cases, and detected the differential expression of TGM3 gene in 8 cases of paired normal and cancerous tissue of laryngeal carcinoma by Northern blot. RESULTS: LOH was found existing in all of the microsatellite loci, and the LOH frequencies were 25.76%, 20.00%, 38.10% and 18.75% at D20S17, D20S607, D20S99 and D20S841 respectively; LOH concerning at least one polymorphism locus accounted for 61.11%. No correlation of clinical stage, lymph node metastasis and differentiation with the LOH of TGM3 gene was observed, P>0.05. TGM3 gene expressed significantly higher in normal tissues than in paired cancerous tissues. CONCLUSION: TGM3 gene might play an important role in laryngeal carcinogenesis and further researches will be needed to clarify the possible mechanisms.

[Homozygous deletion of p16 and p15 genes in laryngeal squamous cell carcinoma].

OBJECTIVE: To assess the relationship of homozygous deletion status of p16 (MTS1/INK4a/CDKN2A), p15(MTS2/INK4b/CDKN2B) genes and laryngeal squamous cell carcinoma(LSCC) progression. METHODS: DNA was extracted from fresh tumors. Homozygous deletion of p16 exon 2(p16E2) in 80 cases of LSCC and p15 exon 2(p15E2) in 67 cases of LSCC were detected by the polymerase chain reaction technique. RESULTS: The p16E2 deletion rate in 80 cases was 12.5%(10/80); the p15E2 deletion rate in 67 cases was 11.94%(8/67); the p16E2 and p15E2 codeletion rate in 67 cases was 5.97%(4/67). CONCLUSION: Homozygous deletion of p16E2 and p15E2 is related with LSCC oncogenesis, and it may play a role to some extent in LSCC malignant progression.

[Expression of STK15 gene and chromosomal instability in laryngeal carcinoma].

To assess the relationship between expression of STK15 gene and chromosomal instability in laryngeal squamous cell carcinoma, RNA was extracted from 50 cases of laryngeal squamous cell carcinoma and paired normal tissue and Hep-2 cell line. cDNA was synthesized through reverse transcription, which was amplified by PCR using beta-actin as contrast. The results of electrophoresis were analysed by software to examine the expression level of STK15 gene in laryngeal carcinoma; karyotype analysis of Hep-2 cell line as an example was performed by routine and high-resolution G-banding techniques. In the 50 cases of laryngeal carcinoma, there were 34 cases whose expression of STK15 gene in tumor was higher than paired normal tissue, occupying 68%. The difference between tumor group and contrast group was prominent by statistic analysis. The expression of STK15 gene in Hep-2 cell line was higher than that of beta-actin; Chromosomal instability in Hep-2 cell line was evident: The chromosomal number range from 43 to 84 and the chromosomal model ranged from 69 to 74. The structural abnormality was represented by 13 marker chromosomes. We discovered the overexpression of STK15 gene in laryngeal carcinoma the first time. It may caused chromosomal instability through abnormal centrosome, therefore having some effect during the occurrence and development of laryngeal carcinoma.