Targeting the chromatin structural changes of antitumor immunity.

Epigenomic imbalance drives abnormal transcriptional processes, promoting the onset and progression of cancer. Although defective gene regulation generally affects carcinogenesis and tumor suppression networks, tumor immunogenicity and immune cells involved in antitumor responses may also be affected by epigenomic changes, which may have significant implications for the development and application of epigenetic therapy, cancer immunotherapy, and their combinations. Herein, we focus on the impact of epigenetic regulation on tumor immune cell function and the role of key abnormal epigenetic processes, DNA methylation, histone post-translational modification, and chromatin structure in tumor immunogenicity, and introduce these epigenetic research methods. We emphasize the value of small-molecule inhibitors of epigenetic modulators in enhancing antitumor immune responses and discuss the challenges of developing treatment plans that combine epigenetic therapy and immunotherapy through the complex interaction between cancer epigenetics and cancer immunology.

Comamonas resistens sp. nov. and Pseudomonas triclosanedens sp. nov., two members of the phylum Pseudomonadota isolated from the wastewater treatment system of a pharmaceutical factory.

Five strains of two novel species were isolated from the wastewater treatment systems of a pharmaceutical factory located in Zhejiang province, PR China. Strains ZM22T and Y6 were identified as belonging to a potential novel species of the genus Comamonas, whereas strains ZM23T, ZM24 and ZM25 were identified as belonging to a novel species of the genus Pseudomonas. These strains were characterized by polyphasic approaches including 16S rRNA gene analysis, multi-locus sequence analysis, average nucleotide identity (ANI), in silico DNA-DNA hybridization (isDDH), physiological and biochemical tests, as well as chemotaxonomic analysis. Genome-based phylogenetic analysis further confirmed that strains ZM22T and Y6 form a distinct clade closely related to Comamonas testosteroni ATCC 11996T and Comamonas thiooxydans DSM 17888T. Strains ZM23T, ZM24 and ZM25 were grouped as a separate clade closely related to Pseudomonas nitroreducens DSM 14399T and Pseudomonas nicosulfuronedens LAM1902T. The orthoANI and isDDH results indicated that strains ZM22T and Y6 belong to the same species. In addition, genomic DNA fingerprinting demonstrated that these strains do not originate from a single clone. The same results were observed for strains ZM23T, ZM24 and ZM25. Strains ZM22T and Y6 were resistant to multiple antibiotics, whereas strains ZM23T, ZM24 and ZM25 were able to degrade an emerging pollutant, triclosan. The phylogenetic, physiological and biochemical characteristics, as well as chemotaxonomy, allowed these strains to be distinguished from their genus, and we therefore propose the names Comamonas resistens sp. nov. (type strain ZM22=MCCC 1K08496T=KCTC 82561T) and Pseudomonas triclosanedens sp. nov. (type strain ZM23T=MCCC 1K08497T=JCM 36056T), respectively.

Revealing a key inhibitory mechanism of 2-amino-3,8-dimethylimidazo[4,5-f] quinoxaline via trapping of methylglyoxal.

The inhibitory effects of vitamins (nicotinic acid, pyridoxamine [PM], and l-ascorbic acid) and phenolic acids (ferulic acid and p-coumaric acid) on the formation of 2-amino-3,8-dimethylimidazo [4,5-f] quinoxaline (MeIQx) were studied in a glycine/glucose/creatinine model system and fried tilapia cakes. The results showed that PM was the most potential inhibitor and the inhibition rates reached 82.72% and 78.54% in model system and fried tilapia cakes, respectively. Detailed formation mechanism of MeIQx was put forward to find the inevitable species in the non-free radical formation mechanism of MeIQx. Dose-dependent analysis of PM on methylglyoxal (MGO ) and MeIQx formation were studied by using model systems and the results showed that MGO and MeIQx were both reduced about 60% in reaction mixtures when the molar ratio of PM to glycine was 1:16, which indicated that MGO is a key intermediate on the pathway of MeIQx formation. Quantum chemistry calculations showed that PM can act as a useful inhibitor to inhibit the formation of MeIQx and react with MGO to form new compounds. A pathway for the inhibitory activity of PM against MeIQx formation was proposed. PRACTICAL APPLICATION: Pyridoxamine was the most effective inhibitor against heterocyclic aromatic amines (HAAs) and could be applied to a variety of food systems. While the inhibitory mechanism is still unclear. Detailed formation mechanism of MeIQx was put forward first and suggested methylglyoxal as an inevitable species in the non-free radical formation mechanism of MeIQx in this study. Pyridoxamine trapping methylglyoxal is likely a key mechanism against the generation of MeIQx was demonstrated by quantum chemistry calculation and experimental demonstration. These findings may provide effective suggestions for reducing HAAs and similar toxicants in daily cuisine.

Potential risk factors associated with prognosis of neoadjuvant chemotherapy followed by interval debulking surgery in stage IIIc-IV high-grade serous ovarian carcinoma patients.

AIM: No consensus has been achieved on the prognostic factors for patients with advanced stage epithelial ovarian cancer who underwent neoadjuvant chemotherapy (NAC) followed by interval debulking surgery (IDS). This study aimed to investigate the prognostic factors for the patients diagnosed as International Federation of Gynecology and Obstetrics stage IIIc-IV high-grade serous ovarian cancer (HG-SOC). METHODS: A total of 200 patients histologically diagnosed as IIIc-IV stage HG-SOC were retrospectively analyzed. All patients underwent platinum-NAC followed by IDS treatment between January 2003 and December 2013. The potential predictive factors (including preoperative ascites volume, cancer antigen 125 [CA-125] and CA-125 decreasing kinetics, NAC and adjuvant chemotherapy cycle number as well as tumor characteristics) for optimal cytoreduction by IDS and for progression free survival (PFS) and overall survival (OS) were assessed. RESULTS: Optimal cytoreduction by IDS was achieved in 78% of HG-SOC patients who underwent NAC. The median number of NAC cycle was 3 (range 1-8). No ascites regression (P < 0.01, odds ratio [OR] = 2.28, 95% confidence interval [CI]: 1.41-3.69), and worse CA-125 decreasing kinetics (P < 0.01, OR = 2.01, 95% CI: 1.37-2.93) were independent predictive factors for suboptimal cytoreduction by IDS. Multivariate regression analysis revealed that PFS and OS were independently associated with preoperative ascites (P < 0.01, hazard ratio [HR] = 2.13, 95% CI: 1.38-3.28 and P < 0.01, HR = 2.33, 95% CI: 1.27-4.26, respectively) and CA-125 decreasing kinetics (P = 0.01, HR = 1.10, 95% CI: 1.02-1.18 and P < 0.01, HR = 1.22, 95% CI: 1.08-1.37, respectively). PFS of patients who underwent more than four NAC cycles was shorter than those of patients who received four or less number of NAC cycles; however, no difference was observed for OS. CONCLUSION: Ascites regression and CA-125 decreasing kinetics were independently associated with the optimal cytoreduction rate and survival of patients diagnosed with advanced stage HG-SOC and treated with NAC/IDS.

Increased EZH2 expression is associated with proliferation and progression of cervical cancer and indicates a poor prognosis.

The objective of this study was to illustrate the role of enhancer zeste homolog 2 (EZH2) overexpression in the proliferation, progression, and prognosis of cervical cancer. We detected EZH2 and Ki-67 expression levels using immunohistochemical (IHC) studies in 20 normal cervical tissues, 50 cervical intraepithelial neoplasia (including 25 low-grade intraepithelial lesions and 25 high-grade intraepithelial lesions), and 101 cervical cancer tissues. The relationships between EZH2 expression and Ki-67 expression, conventional clinicopathologic characteristics of cervical cancer, and patient outcomes were evaluated. The effect of EZH2 expression on cancer-specific survival was assessed by multivariate Cox regression analysis. Positive expression of EZH2 was detected in 10% (2/20) of the normal cervical tissues, 52% (13/25) of the low-grade squamous intraepithelial lesions, 64% (16/25) of the high-grade squamous intraepithelial lesions, and 68.3% (69/101) of the cervical cancer tissues. The expression of Ki-67 was positively correlated with EZH2 expression: 5% (1/20) in normal cervical tissues, 48% (12/25) in low-grade squamous intraepithelial lesions, 52% (13/25) in high-grade squamous intraepithelial lesions, and 57.4% (58/101) in cervical cancer tissues. Overexpression of EZH2 was adversely associated with clinical stage, histologic differentiation, infiltration depth, and lymph node metastasis (P<0.05). Patients with EZH2-positive expression showed a decreased overall survival compared with those with EZH2-negative expression (P=0.003, log-rank test). Multivariate Cox regression analysis suggested that overexpression of EZH2 was an independent predictor of poor prognosis in cervical cancer. Overexpression of EZH2 was closely associated with the carcinogenesis, proliferation, clinical and biologic behaviors, and the prognosis of cervical cancer, suggesting that it might be used as a potential predictor of prognosis in cervical cancer.

Overexpression of TROP2 predicts poor prognosis of patients with cervical cancer and promotes the proliferation and invasion of cervical cancer cells by regulating ERK signaling pathway.

Overwhelming evidence has demonstrated that the aberrant expression of the human trophoblast cell-surface antigen (TROP2) was associated with tumor aggressiveness and poor prognosis in a variety of human cancers, however the roles of TROP2 in cervical cancer have not been investigated. The purpose of our study was to elucidate the prognostic significance of TROP2 expression in patients with cervical cancer and determine its effect on tumor progression. Immunohistochemistry assay showed that 88.7% (94/106 cases) of cervical cancer specimens were positively stained with TROP2, and the overexpression of TROP2 was closely related with FIGO stage, histological grades, lymphatic metastasis, invasive interstitial depth and high expression of Ki-67. Patients with TROP2-positive staining exhibited a significantly decreased overall survival and progression free survival; it was also an independent predictor for prognosis according to multivariate analysis. Moreover, down-regulation of TROP2 mediated by siRNA in Siha and CaSki cells resulted in a strong inhibition of proliferation and invasion, TROP2 abrogation also elevated the apoptotic ratio and caused G1 arrest. Conversely, enforced expression of TROP2 in HeLa and C33A cells remarkably promoted cell growth, migration and invasion. In addition, the tumorigenic function of TROP2 was associated with the increased expressions of cyclin D1, cyclin E, CDK2 and CDK4 but reduced expression of p27 and E-cadherin via the activation of Erk1/2 signaling pathway. Furthermore, the inhibition of TROP2 expression in cervical cancer cell lines enhances sensitivity to cisplatin. The present study suggest that overexpression of TROP2 may play crucial roles in the development and pathogenesis of human cervical cancer, therefore, TROP2 may represent a prospective prognostic indicator and a potential therapeutic target of cervical cancer.

Overexpression of PRMT5 promotes tumor cell growth and is associated with poor disease prognosis in epithelial ovarian cancer.

PRMT5 has been reported to be involved in the processes of tumor progression at various steps. The aim of this study was to examine the role of PRMT5 in epithelial ovarian cancer (EOC). In this study, PRMT5 and Ki-67 expression were examined by immunohistochemistry (IHC) in cohorts of normal, benign, and cancerous ovarian tissues. PRMT5 overexpression was observed in 83.1% (98/118) of EOCs, and it was significantly associated with serous type, poor differentiation, advanced tumor stage, lymph node invasion, presence of residual tumor, and high expression of Ki-67 (p<0.05, respectively). Moreover, overexpression of PRMT5 was an independent prognostic marker for decreased overall survival and progression-free survival in univariate survival analysis and multivariate Cox regression analysis. In ovarian cancer cell lines A2780 and SKOV3, PRMT5 knockdown by siRNA inhibited cell growth/proliferation and induced apoptosis via upregulation of E2F-1. These results suggest that overexpression of PRMT5 correlates with an aggressive malignant phenotype and may constitute a novel prognostic factor for EOC. Thus, PRMT5 may represent a clinically effective new target for therapy of ovarian cancer.