The role of lipid peroxidation in epithelial-mesenchymal transition of retinal pigment epithelial cells.

Epithelial-Mesenchymal Transition (EMT) of retinal pigment epithelial (RPE) cells is recognized as pivotal in various retinal diseases. Previous studies have suggested a reciprocal regulation between reactive oxygen species (ROS) and EMT, though the involvement of peroxidized lipids or the effects of reducing them has remained unclear. The present study disclosed that EMT of ARPE-19 cells induced by TGF-ß2 and TNF-α involves increased lipid peroxidation, and Ferrostatin-1 (Fer-1), a lipophilic antioxidative agent, successfully inhibited the increase in lipid peroxidation. Fer-1 suppressed the formation of EMT-associated fibrotic deposits, while EMT induction or Fer-1 treatment did not influence the cell viability or proliferation. Functionally, Fer-1 impeded EMT-driven cell migration and reduction in transepithelial electrical resistance. It demonstrated regulatory prowess by downregulating the mesenchymal marker fibronectin, upregulating the epithelial marker ZO-1, and inhibiting the EMT-associated transcriptional factor ZEB1. Additionally, VEGF, a major pathogenic cytokine in various retinal diseases, is also upregulated during EMT, and Fer-1 significantly mitigated the effect. The present study disclosed the involvement of lipid peroxidation in EMT of RPE cells, and suggests the suppression of lipid peroxidation may be a potential therapeutic target in retinal diseases in which EMT is implicated.

Early results of the integrative epigenomic-transcriptomic landscape of colorectal adenoma and cancer.

BACKGROUND: Aberrant methylation is common during the initiation and progression of colorectal cancer (CRC), and detecting these changes that occur during early adenoma (ADE) formation and CRC progression has clinical value. AIM: To identify potential DNA methylation markers specific to ADE and CRC. METHODS: Here, we performed SeqCap targeted bisulfite sequencing and RNA-seq analysis of colorectal ADE and CRC samples to profile the epigenomic-transcriptomic landscape. RESULTS: Comparing 22 CRC and 25 ADE samples, global methylation was higher in the former, but both showed similar methylation patterns regarding differentially methylated gene positions, chromatin signatures, and repeated elements. High-grade CRC tended to exhibit elevated methylation levels in gene promoter regions compared to those in low-grade CRC. Combined with RNA-seq gene expression data, we identified 14 methylation-regulated differentially expressed genes, of which only AGTR1 and NECAB1 methylation had prognostic significance. CONCLUSION: Our results suggest that genome-wide alterations in DNA methylation occur during the early stages of CRC and demonstrate the methylation signatures associated with colorectal ADEs and CRC, suggesting prognostic biomarkers for CRC.

Integration of metabolomics and transcriptomics analyses reveals sphingosine-1-phosphate-mediated S1PR2/PI3K/Akt pathway involved in Talaromyces marneffei infection of macrophages.

Talaromycosis is a fatal mycosis caused by the thermally dimorphic fungus Talaromyces marneffei (T. marneffei). The pathogenic mechanisms of talaromycosis are still poorly understood. This work combined metabolomics, transcriptomics, and verification experiments in vivo and in vitro to detect metabolic profiles and differentially expressed genes (DEGs) in T. marneffei infected and uninfected macrophages to explore possible pathogenesis and underlying mechanisms. A total of 256 differential metabolites (117 up-regulated and 148 down-regulated) and 1320 DEGs (1286 up-regulated and 34 down-regulated) were identified between the two groups. Integrative metabolomics and transcriptomics analysis showed sphingolipid signaling pathway is the most influential. Verification experiments showed that compared with the control group, the production of sphingosine-1-phosphate (S1P) and the expression of the S1PR1, S1PR2, phosphor-PI3K, and phosphor-Akt genes involved in the sphingolipid signaling pathway have significantly increased in the T. marneffei infection group (p < 0.05). T. marneffei activates the S1PR2/PI3K/Akt pathways in J774A.1 macrophage, regulation of the S1P singling might serve as a promising therapeutic strategy for talaromycosis.

[Effects of rapamycin on glucose-induced autophagy and apoptosis of corpus cavernosum smooth muscle cells in SD rats].

OBJECTIVE: To observe the effects of rapamycin on glucose-induced autophagy and apoptosis of corpus cavernosum smooth muscle cells (CCSMC) in SD rats. METHODS: After primary isolation, purification and identification, CCSMCs were treated with glucose at 5.6, 10, 20, 30 and 40 mmol/L for 48 hours. The autophagy flow was detected in the cells transfected with mCherry-GFP-LC3B double fluorescent adenovirus, the protein and mRNA expressions of autophagy-related gene 5 (ATG5), microtubule-associated protein 1 light chain 3 (LC3), P62 and Beclin-1 determined by Western blot and PCR and the apoptosis of the CCSMC measured by flow cytometry, followed by detection of the changes in the protein and mRNA levels of LC3, Beclin-1 and P62 and the apoptosis of the cells after 2-hour pretreatment with 600 nmol/L rapamycin and then 48-hour treatment with 40 mmol/L glucose. RESULTS: Autophagy was observed in the CCSMCs treated with different concentrations of glucose, the strongest in the 10 mmol/L group (P < 0.05) and then gradually decreasing with the increase of glucose concentration (P < 0.05). The apoptosis rate of the CCSMCs was remarkably increased in a concentration-dependent manner after treated with glucose (P < 0.01) though with no statistically significant difference between the 5.6 and 10 mmol/L groups (P = 0.302). After pretreatment with rapamycin, the expression of the LC3 protein and those of the Beclin-1 protein and mRNA were markedly up-regulated (P < 0.05), while those of the P62 protein and mRNA remarkably down-regulated (P < 0.05), indicating the enhancement of autophagy, and the apoptosis rate of the CCSMCs dramatically decreased (P < 0.01). CONCLUSIONS: In vitro culture of CCSMCs with glucose within a certain range of concentration can promote autophagy, inhibit the apoptosis and thus have a protective effect on the cells, but when the proper concentration exceeded, it may also reduce autophagy, promote the apoptosis and consequently affect the vitality and function of CCSMCs.

Research progress on genetic heterogeneity between primary and paired metastatic colorectal cancer.

Colorectal cancer (CRC) is one of the leading causes of cancer deaths in China. A standard practice in treating metastatic CRC (mCRC) is to predict benefits of the anti-EGFR monoclonal antibody treatment based on the somatic mutation spectrum. Because metastatic samples are difficult to obtain clinically, primary tumors are normally used instead. However, due to the genetic heterogeneity between primary and paired metastatic tumors, primary site biopsy always underrepresents the mutational landscape of metastatic sites. Currently, the extent of genetic heterogeneity between primary and paired mCRC is still under debate. Here, we review comparative studies of primary and matched mCRC and discuss the underlying causes and potential strategies.

Relationship Between Human mutL Homolog 1 (hMLH1) Hypermethylation and Colorectal Cancer: A Meta-Analysis.

BACKGROUND Hypermethylation of CpG islands in gene promoter regions is an important mechanism of gene inactivation in cancers. Promoter hypermethylation of human mutL homolog 1 (hMLH1) has been implicated in a subset of colorectal cancers that show microsatellite instability (MSI), while the connection of the epigenetic inactivation of hMLH1 in colorectal cancers remains unknown. The aim of this study was to evaluate the relationship between the promoter hypermethylation of hMLH1 and colorectal cancers by performing a meta-analysis. MATERIAL AND METHODS Eligible studies were identified through searching PubMed, Cochrane Library, Web of Science, and Google Scholar databases. R Software including meta packages was used to calculate the pooled and odds ratios (ORs) with corresponding confidence intervals (CIs). Funnel plots were also performed to evaluate publication bias. RESULTS This meta-analysis obtained 45 articles, including 4096 colorectal cancer patients, and identified a significant association between hMLH1 hypermethylation and colorectal cancer risk using the fixed-effects model (OR=8.3820; 95% CI, 6.9202~10.1527; z=21.7431; P<0.0001) and random effects model pooled (OR=10.0963; 95% CI, 6.1919~16.4626; z=9.2688; P<0.0001). The significant relationship was found in subgroup analyses. CONCLUSIONS The results of this meta-analysis show a significant association between hMLH1 hypermethylation and colorectal cancer risk.

Colorectal Cancer Genetic Heterogeneity Delineated by Multi-Region Sequencing.

Intratumor heterogeneity (ITH) leads to an underestimation of the mutational landscape portrayed by a single needle biopsy and consequently affects treatment precision. The extent of colorectal cancer (CRC) genetic ITH is not well understood in Chinese patients. Thus, we conducted deep sequencing by using the OncoGxOne™ Plus panel, targeting 333 cancer-specific genes in multi-region biopsies of primary and liver metastatic tumors from three Chinese CRC patients. We determined that the extent of ITH varied among the three cases. On average, 65% of all the mutations detected were common within individual tumors. KMT2C aberrations and the NCOR1 mutation were the only ubiquitous events. Subsequent phylogenetic analysis showed that the tumors evolved in a branched manner. Comparison of the primary and metastatic tumors revealed that PPP2R1A (E370X), SETD2 (I1608V), SMAD4 (G382T), and AR splicing site mutations may be specific to liver metastatic cancer. These mutations might contribute to the initiation and progression of distant metastasis. Collectively, our analysis identified a substantial level of genetic ITH in CRC, which should be considered for personalized therapeutic strategies.

Gene regulatory cascade of senescence-associated NAC transcription factors activated by ETHYLENE-INSENSITIVE2-mediated leaf senescence signalling in Arabidopsis.

Leaf senescence is a finely tuned and genetically programmed degeneration process, which is critical to maximize plant fitness by remobilizing nutrients from senescing leaves to newly developing organs. Leaf senescence is a complex process that is driven by extensive reprogramming of global gene expression in a highly coordinated manner. Understanding how gene regulatory networks involved in controlling leaf senescence are organized and operated is essential to decipher the mechanisms of leaf senescence. It was previously reported that the trifurcate feed-forward pathway involving EIN2, ORE1, and miR164 in Arabidopsis regulates age-dependent leaf senescence and cell death. Here, new components of this pathway have been identified, which enhances knowledge of the gene regulatory networks governing leaf senescence. Comparative gene expression analysis revealed six senescence-associated NAC transcription factors (TFs) (ANAC019, AtNAP, ANAC047, ANAC055, ORS1, and ORE1) as candidate downstream components of ETHYLENE-INSENSITIVE2 (EIN2). EIN3, a downstream signalling molecule of EIN2, directly bound the ORE1 and AtNAP promoters and induced their transcription. This suggests that EIN3 positively regulates leaf senescence by activating ORE1 and AtNAP, previously reported as key regulators of leaf senescence. Genetic and gene expression analyses in the ore1 atnap double mutant revealed that ORE1 and AtNAP act in distinct and overlapping signalling pathways. Transient transactivation assays further demonstrated that ORE1 and AtNAP could activate common as well as differential NAC TF targets. Collectively, the data provide insight into an EIN2-mediated senescence signalling pathway that coordinates global gene expression during leaf senescence via a gene regulatory network involving EIN3 and senescence-associated NAC TFs.

Neoadjuvant chemotherapy followed by concurrent chemoradiation for locally advanced nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: Concurrent chemoradiation therapy (CCRT) is the standard treatment for patients with locally advanced nasopharyngeal carcinoma (NPC). The effect of neoadjuvant chemotherapy followed by CCRT has not been determined. Therefore, we conducted 2 phase II studies to evaluate the efficacy and safety of neoadjuvant chemotherapy with a regimen of docetaxel, cisplatin, and 5 fluorouracil (5-Fu) (TPF) followed by radiotherapy and concurrent cisplatin in patients with stage III and IV(A - B) NPC. This article is the preliminary report on treatment related toxicities and response. METHODS: Graded according to the 2002 American Joint Committee on Cancer (AJCC) staging criteria, only patients with stage III or IV(A-B) poorly differentiated or undifferentiated NPC (World Health Organization type II/III) were included. We planned to recruit 52 patients with stage III disease and 64 patients with stage IV(A - B) disease. All patients received neoadjuvant chemotherapy with TPF (docetaxel 75 mg/m(2), day 1; cisplatin 75 mg/m(2), day 1; 5 Fu 500 mg/(m2 x day), continuous intravenous infusion for 120 h), every 3 weeks for 3 cycles, followed by weekly cisplatin (40 mg/m(2)) concurrent with radiotherapy. Three dimensional conformal radiotherapy (3D CRT) and intensity modulated radiotherapy (IMRT) were used. Gross disease planning target volume (PTV), high risk and low risk subclinical PTV doses were prescribed at 70-76 Gy, 66-70 Gy, and 60-61.25 Gy at 1.75-2.0 Gy per fraction. The lower neck or supraclavicular fields may be treated with conventional AP/PA fields for a total of 54 Gy at 1.8 Gy per fraction. Patients were evaluated for tumor response after the completion of neoadjuvant chemotherapy, and at 3 months after radiation according to the Response Evaluation Criteria In Solid Tumors (RECIST). The latest version of the National Cancer Institute's Common Terminology Criteria for Adverse Events (NCI CTCAE 3.0) was used for grading all adverse events. RESULTS: Fifty nine patients were evaluable for treatment response. Thirty patients had stage III disease and 29 patients had stage IV(A-B). All patients completed RT to the prescribed dose and 2 cycles of neoadjuvant chemotherapy, with 51 patients (86.4%) completing 3 cycles. A total of 50 (84.7%) and 39 patients (66.1%) completed 4 weeks and 5 weeks of cisplatin during CCRT, respectively. The overall response rate in the primary site and the neck region were 94.9% [complete response (CR) in 25.4%] and 100% (CR in 19.6%) after completing neoadjuvant chemotherapy. At 3 months after RT, the CR rates increased to 96.6% and 90.2%, respectively. After a median follow up of 14.3 months, we observed 5 treatment failures and 2 deaths. The 1 year overall survival, distant metastasis free survival, and locoregional relapse free survival rates were 100%, 95.7%, and 97.7%, respectively. The rates of grade 3/4 myelosuppression and anorexia/nausea/vomiting during neoadjuvant chemotherapy were 55.9% and 16.9%, respectively. The corresponding rates were 11.9% and 23.7% during CCRT. Grade 3/4 mucositis, skin desquamation, and xerostomia occurred in 6.8%, 44.1%, and 27.1% of patients, respectively. There were no treatment related deaths. CONCLUSIONS: Neoadjuvant chemotherapy with TPF followed by CCRT was well tolerated with a manageable toxicity profile. Preliminary results are encouraging and warrant further investigation.