The DNA Phosphorothioation Restriction-Modification System Influences the Antimicrobial Resistance of Pathogenic Bacteria.

Bacterial defense barriers, such as DNA methylation-associated restriction-modification (R-M) and the CRISPR-Cas system, play an important role in bacterial antimicrobial resistance (AMR). Recently, a novel R-M system based on DNA phosphorothioate (PT) modification has been shown to be widespread in the kingdom of Bacteria as well as Archaea. However, the potential role of the PT R-M system in bacterial AMR remains unclear. In this study, we explored the role of PT R-Ms in AMR with a series of common clinical pathogenic bacteria. By analyzing the distribution of AMR genes related to mobile genetic elements (MGEs), it was shown that the presence of PT R-M effectively reduced the distribution of horizontal gene transfer (HGT)-derived AMR genes in the genome, even in the bacteria that did not tend to acquire AMR genes by HGT. In addition, unique gene variation analysis based on pangenome analysis and MGE prediction revealed that the presence of PT R-M could suppress HGT frequency. Thus, this is the first report showing that the PT R-M system has the potential to repress HGT-derived AMR gene acquisition by reducing the HGT frequency. IMPORTANCE In this study, we demonstrated the effect of DNA PT modification-based R-M systems on horizontal gene transfer of AMR genes in pathogenic bacteria. We show that there is no apparent association between the genetic background of the strains harboring PT R-Ms and the number of AMR genes or the kinds of gene families. The strains equipped with PT R-M harbor fewer plasmid-derived, prophage-derived, or integrating mobile genetic element (iMGE)-related AMR genes and have a lower HGT frequency, but the degree of inhibition varies among different bacteria. In addition, compared with Salmonella enterica and Escherichia coli, Klebsiella pneumoniae prefers to acquire MGE-derived AMR genes, and there is no coevolution between PT R-M clusters and bacterial core genes.

Large pelvic mass arising from the cervical stump: A case report.

BACKGROUND: A large cervical cyst with a cervical high-grade squamous intraepithelial lesion arising from the cervical stump is rare. After supracervical hysterectomy, there is a risk of various lesions occurring in the cervical stump. We review the types and characteristics of cervical stump lesions and compare total hysterectomy with subtotal hysterectomy. Gynecologists should choose the most suitable surgical method based on both the patient's condition and wishes. If the cervix is retained, patients require a close follow-up. CASE SUMMARY: A 57-year-old woman was admitted to the Gynecology Department for a large pelvic mass. Her chief complaint was abdominal distention for two months. She had undergone subtotal supracervical hysterectomy for leiomyoma 14 years prior. Abdominal ultrasonography detected a 9.1 cm × 8.5 cm × 8.4 cm anechoic mass with silvery fluid in the pelvic cavity and high-risk human papilloma virus 53 (HPV53) was positive. The admission diagnosis we first considered was a pelvic mass mimicking carcinoma of the cervical stump. We performed a laparotomy and a rapid frozen biopsy was suggestive of a fibrous cyst wall coated with a high squamous intraepithelial lesion. The pelvic mass was removed, and a bilateral adnexectomy was implemented. Final pathology confirmed that the pelvic mass was a large inflammatory cyst with a cervical high-grade squamous intraepithelial lesion. After successful intervention, the patient was discharged one week after surgery and there was no recurrence of the vaginal stump at 43 mo. CONCLUSION: When addressing benign uterine diseases, gynecologists should pay adequate attention to retaining the cervix. If the cervix is retained, patients require a close follow-up.

MicroRNA-135a-3p is downregulated and serves as a tumour suppressor in ovarian cancer by targeting CCR2.

MicroRNAs have been demonstrated to play a crucial role in the development of ovarian cancer. Many studies prove that forms of miR-135a, including miR-135a-5p and miR-135a-3p, serve as tumour suppressors in multiple cancers. Nevertheless, the precise function of miR-135a-3p and the molecular mechanisms underlying the involvement of miR-135a-3p in ovarian carcinoma cell growth and metastasis remain largely unknown. Herein, we report that miR-135a-3p expression was significantly downregulated in ovarian carcinoma tissues compared with corresponding adjacent non-tumour tissues. Ectopic miR-135a-3p expression inhibited ovarian carcinoma cell proliferation, migration and invasion in vitro. Additionally, the overexpression of miR-135a-3p inhibited epithelial-mesenchymal transition (EMT) in ovarian cancer cells. A luciferase reporter assay confirmed that the C-C chemokine receptor type 2 (CCR2) gene was the target of miR-135a-3p. In addition, CCR2 depletion mimicked the inhibitory effects of miR-135a-3p on ovarian cancer cells in vitro. Rescue experiments using CCR2 overexpression further verified that CCR2 was a functional target of miR-135a-3p. Xenograft model assays demonstrated that miR-135a-3p functions as an anti-oncogene by targeting CCR2 in vivo. Taken together, these data prove that miR-135a-3p serves as a tumour suppressor gene in ovarian cancer by regulating CCR2.

Discrepant clinicopathologic characteristics and HE4 performance in type I and type II epithelial ovarian cancer.

Recent studies have demonstrated that epithelial ovarian cancer (EOC) are factual several different diseases. A two-tier system divides EOC into type I and type II EOC. HE4 has been used as a complementary biomarker for diagnosing EOC. This study aimed to evaluate the different clinicopathologic characteristics and HE4 expression levels in types I and II EOCs. This retrospective study included 127 EOC patients. Data related to patient demographics, cancer stages, grades, histology, operation procedures, residual disease, adjuvant chemotherapy, recurrence, and survival were collected. A total of 134 ovarian carcinoma tissue specimens and 40 matching borderline ovarian tumor specimens were chosen from the pathology department archives. Immunohistochemistry was used to assess HE4 expression in EOC and borderline ovarian tumor tissue specimens. Of the 127 patients, there were 42 type I EOC patients (7 low grade serous carcinomas, 8 mucinous carcinomas, 12 low grade endometrioid carcinomas and 15 clear cell carcinomas) and 85 type II EOC patients (83 high grade serous carcinomas and 2 high grade endometrioid carcinomas). The median followed--up time was 18.3 months. There were significant differences between the two types of EOC in terms of the menopausal state, FIGO stage and pathological differentiation, but there were no differences in the residual tumor and chemotherapy treatment. In type I EOC, the median follow--up time was 31 months and the median progression--free survival was 72 months (95% CI: 40.34-103.66). There were 15 (35.7%) relapsed or progressive patients. In type II EOC, the median follow-up time was 17 months (0-60 m), and the median progression--free survival was 27 months (95% CI: 17.83-36.17). There were 47 (55.3%) relapsed or progressive patients. There was a significant difference between the two types of EOCs in terms of progression--free survival (P<0.001). Among the 44 type I specimens, 25 demonstrated positive expression of HE4 (56.8%). In contrast, 78 (86.7%) type II EOC demonstrated positive expression levels. There was a significant difference between type I and type II EOCs in terms of HE4 expression. Additionally, there was a significant difference between high grade serous carcinoma and borderline serous tumor, but no difference was observed between low grade serous carcinoma and borderline serous tumor or other types of EOC and corresponding borderline tumors. The different clinicopathologic characteristics between type I and type II EOC indicate that the two--tier EOC system reasonable and reliable. HE4 would be a powerful biomarker to distinguish type II EOC from borderline tumors but it is less useful in type I EOC. Type I EOC is generated from the corresponding borderline tumor.

siRNA combinations mediate greater suppression of hepatitis B virus replication in mice.

Hepatitis B virus (HBV) infection is a major world-wide health problem. The major obstacles for current anti-HBV therapy are the low efficacy and the occurrence of drug resistant HBV mutations. Recent studies have demonstrated that combination therapy can enhance antiviral efficacy and overcome shortcomings of established drugs. In this study, the inhibitory effect mediated by combination of siRNAs targeting different sites of HBV in transgenic mice was analyzed. HBsAg and HBeAg in the sera of the mice were analyzed by enzyme-linked immunoadsorbent assay, HBV DNA by real-time PCR and HBV mRNA by RT-PCR. Our data demonstrated that all the three siRNAs employed showed marked anti-HBV effects. The expression of HBsAg and the replication of HBV DNA could be specifically inhibited in a dose-dependent manner by siRNAs. Furthermore, combination of siRNAs compared with individual use of each siRNA, exerted a stronger inhibition on antigen expression and viral replication, even though the final concentration of siRNA used for therapy was the same. Secreted HBsAg and HBeAg in the serum of mice treated with siRNA combination were reduced by 96.7 and 96.6 %, respectively. Immunohistochemical detection of liver tissue revealed 91 % reduction of HBsAg-positive cells in the combination therapy group. The combination of siRNAs caused a greater inhibition in the levels of viral mRNA and DNA (90 and 87.7 %) relative to the control group. It was noted that the siRNA3 showed stronger inhibition of cccDNA (78.6 %). Our results revealed that combination of siRNAs mediated a stronger inhibition of viral replication and antigen expression in transgenic mice than single siRNAs.

[Mechanism of anti-tumor effect of HIF-1alpha silencing on cervical cancer in nude mice].

OBJECTIVE: To observe the anti-tumor effect of silencing the expression of HIF-1alpha on cervical cancer in nude mice and to explore its mechanism of action. METHODS: Human cervical cancer cell line Siha cells were divided into 3 groups: mock control group, control group transfected with scrambled sequence plasmid, and experimental group transfected with pU-HIF-1alpha-shRNA eukaryotic expression plasmid. Cultured cells of the three groups were inoculated in nude mice to establish cervical cancer-bearing nude mice. HIF-1alpha RNAi assay was performed to evaluate the tumor-suppressive effect of HIF-1alpha silencing on cervical cancer-bearing nude mice. Immunohistochemistry and Western blot were used to observe the distribution and protein expression of HIF-1alpha and GLUT1, while RT-PCR was adopted to detect the gene expression of HIF-1alpha, GLUT1 and HKII. The product of glycolysis (lactic acid) and apoptosis in tumor cells were detected by colorimetry and semi-quantitative TUNEL staining, respectively. RESULTS: The tumor growth in experimental group was significantly slower than that in the two control groups (P < 0.05). On the 50th day after transplantation, the tumor weight in the experimental group was (1.90 +/- 0.28) g, significantly lower than (2.95 +/- 0.77) g in the control group and (2.54 +/- 0.56) g in the mock group (P < 0.01). In the experimental group, the gene and protein levels of HIF-1alpha were 0.45 +/- 0.04 and 1.25 +/- 0.92, and the levels of GLUT1 were 0.32 +/- 0.02 and 1.25 +/- 0.48, respectively. Both indicators in HIF-1alpha and GLUT1 were lower than that in the two control groups (P < 0.05). The expression levels of HKII gene and lactic acid in the experimental group were lower than that in the two control groups (P < 0.05), but the apoptotic cells were much more numerous in the experimental group than that in matched control groups (P < 0.01). CONCLUSION: The gene therapy by siRNA targeted silencing of HIF-1alpha may down-regulate its downstream genes GLUT1 and HKII expression, therefore, to reduce the tumor glycolysis activity and promote tumor cell apoptosis, and exert a tumor-suppressing effect in vivo.