Auto-suppression of Tet dioxygenases protects the mouse oocyte genome from oxidative demethylation.

DNA cytosine methylation plays a vital role in repressing retrotransposons, and such derepression is linked with developmental failure, tumorigenesis and aging. DNA methylation patterns are formed by precisely regulated actions of DNA methylation writers (DNA methyltransferases) and erasers (TET, ten-eleven translocation dioxygenases). However, the mechanisms underlying target-specific oxidation of 5mC by TET dioxygenases remain largely unexplored. Here we show that a large low-complexity domain (LCD), located in the catalytic part of Tet enzymes, negatively regulates the dioxygenase activity. Recombinant Tet3 lacking LCD is shown to be hyperactive in converting 5mC into oxidized species in vitro. Endogenous expression of the hyperactive Tet3 mutant in mouse oocytes results in genome-wide 5mC oxidation. Notably, the occurrence of aberrant 5mC oxidation correlates with a consequent loss of the repressive histone mark H3K9me3 at ERVK retrotransposons. The erosion of both 5mC and H3K9me3 causes ERVK derepression along with upregulation of their neighboring genes, potentially leading to the impairment of oocyte development. These findings suggest that Tet dioxygenases use an intrinsic auto-regulatory mechanism to tightly regulate their enzymatic activity, thus achieving spatiotemporal specificity of methylome reprogramming, and highlight the importance of methylome integrity for development.

Paclitaxel liposome (Lipusu) based chemotherapy combined with immunotherapy for advanced non-small cell lung cancer: a multicenter, retrospective real-world study.

BACKGROUND: Paclitaxel liposome (Lipusu) is known to be effective in non-small cell lung cancer (NSCLC) as first-line treatment. This study aimed to evaluate the effectiveness and safety of paclitaxel liposome based chemotherapy plus PD-1/PD-L1 inhibitor in patients with advanced NSCLC. METHODS: In this multicenter, retrospective, real-world study, patients with advanced NSCLC who were administered paclitaxel liposome based chemotherapy plus PD-1/PD-L1 inhibitor in three centers (Peking University People's Hospital as the lead center) in China between 2016 and 2022 were included. Progression-free survival (PFS), overall survival (OS), objective response rate, disease control rate, and adverse events (AEs) were evaluated. RESULTS: A total of 49 patients were included, with 33 (67.3%) receiving paclitaxel liposome based chemotherapy plus PD-1/PD-L1 inhibitor as first-line treatment. There were 34 patients (69.4%) diagnosed with squamous cell carcinoma and 15 (30.6%) with adenocarcinoma. The median follow-up was 20.5 (range: 3.1-41.1) months. The median PFS and OS of all patients were 9.7 months (95% confidence interval [CI], 7.0-12.4) and 30.5 months (95% CI, not evaluable-not evaluable), respectively. Patients with squamous cell carcinoma and adenocarcinoma had median PFS of 11 months (95%CI, 6.5-15.5) and 9.3 months (95%CI, 7.0-12.4), respectively. The median PFS was 9.9 months (95%CI, 7.1-12.7) in patients who received the combined regimen as first-line treatment. Treatment-related AEs of any grade were observed in 25 (51.0%) patients, and AEs of grade 3 or worse were observed in nine patients (18.4%). The most common treatment-related AEs were myelosuppression (14.3%) and fever (10.2%). CONCLUSIONS: Paclitaxel liposome based chemotherapy plus PD-1/PD-L1 inhibitor prolonged the PFS in advanced NSCLC with acceptable safety, which was worthy of clinical application.

LncRNA LINC00520 Predicts Poor Prognosis and Promotes Progression of Lung Cancer by Inhibiting MiR-3175 Expression.

PURPOSE: The aim of this study was to study the roles and potential mechanism of LINC00520 in the progression of lung cancer. METHODS: The expression of LINC00520 and miR-3175 in lung cancer tissues and cells was detected by qRT-PCR. The relationship between LINC00520 level and disease stage was also calculated. Kaplan-Meier survival curve was drawn to observe the survival difference between high and low expression patients. Lipofectamine 2000 was used to transfect siLINC00520, miR-3175 inhibitor and their controls in lung cancer cells. CCK8 and colony formation assay were processed for cell proliferation. Transwell assay was undertaken for migration and invasion of lung cancer cells. MiRDB predicts the combination of LINC00520 and miR-3175. Luciferase and RNA pulldown assay were applied to verify the binding site. Correlation analysis of miR-3175 and LINC00520 expression in lung cancer tissues was shown. RESULTS: LINC00520 was highly expressed in lung cancer tissues and cells. Patients at III+IV stage were always with higher LINC00520 level than patients at I+II stage. Patients with high expression of lncRNA LINC00520 have short survival time (hazard ratio=1.7). Knockdown of LINC00520 inhibited proliferation, invasion and migration of lung cancer cells. LINC00520 targeted and negatively regulated miR-3175 (r=-0.528; P<0.001). MiR-3175 inhibitor rescued the effect of si-LINC00520 on lung cancer progression. CONCLUSION: LncRNA LINC00520 could predict poor prognosis and promote progression of lung cancer by inhibiting miR-3175 expression.

Palliative Locoregional Treatment for Unresectable Nonmetastatic Klatskin Tumor: Percutaneous Transhepatic Biliary Drainage Combined With 3-dimensional Conformal Radiotherapy.

PURPOSE: This study aimed to identify the effect of percutaneous transhepatic biliary drainage (PTBD) combined with 3-dimensional conformal radiotherapy (3D-CRT) in comparison with PTBD therapy only on the treatment of unresectable Klatskin tumors (KTs). MATERIALS AND METHODS: Thirty-seven patients with unresectable KTs were included in the study. Twenty-six patients received PTBD and 3D-CRT successively, whereas the other 11 patients received PTBD only. Changes in the clinical symptoms after the PTBD treatment, the radiotherapy effect, and the survival time were recorded and analyzed. RESULTS: The clinical symptoms of the 2 groups gradually decreased after the PTBD treatment. The radiotherapy effect showed an overall effective rate (complete response+partial response) of 17 (65.38%), and the serum carbohydrate antigen-19-9 levels before and after 3D-CRT were significantly different (P<0.001). The mean survival time of the PTBD group was 11.27 months; the 1- and 2-year cumulative survival rates were 36.4% and 9.1%, respectively. The mean survival time of the combined therapy group was 22.77 months; the 1-, 2-, and 3-year cumulative survival rates were 53.8%, 38.5%, and 11.5%, respectively. The log-rank test showed that the patients who received combined therapy had longer survival time than the patients who only received PTBD (P=0.001). CONCLUSIONS: Patients with unresectable KTs who underwent PTBD could relieve biliary obstruction effectively. Although this study is not a randomized trial, 3D-CRT combined with PTBD seems to be a promising and an effective method as a palliative treatment for unresectable KTs.

Targeted lung cancer therapy: preparation and optimization of transferrin-decorated nanostructured lipid carriers as novel nanomedicine for co-delivery of anticancer drugs and DNA.

PURPOSE: Nanostructured lipid carriers (NLC) represent an improved generation of lipid nanoparticles. They have specific nanostructures to accommodate drugs/genes, and thus achieve higher loading capacity. The aim of this study was to develop transferrin (Tf)-decorated NLC as multifunctional nanomedicine for co-delivery of paclitaxel (PTX) and enhanced green fluorescence protein plasmid. METHODS: Firstly, Tf-conjugated ligands were synthesized. Secondly, PTX- and DNA-loaded NLC (PTX-DNA-NLC) was prepared. Finally, Tf-containing ligands were used for the surface decoration of NLC. Their average size, zeta potential, drug, and gene loading were evaluated. Human non-small cell lung carcinoma cell line (NCl-H460 cells) was used for the testing of in vitro transfection efficiency, and in vivo transfection efficiency of NLC was evaluated on mice bearing NCl-H460 cells. RESULTS: Tf-decorated PTX and DNA co-encapsulated NLC (Tf-PTX-DNA-NLC) were nano-sized particles with positive zeta potential. Tf-PTX-DNA-NLC displayed low cytotoxicity, high gene transfection efficiency, and enhanced antitumor activity in vitro and in vivo. CONCLUSION: The results demonstrated that Tf-PTX-DNA-NLC can achieve impressive antitumor activity and gene transfection efficiency. Tf decoration also enhanced the active targeting ability of the carriers to NCl-H460 cells. The novel drug and gene delivery system offers a promising strategy for the treatment of lung cancer.

Cytokines: shifting the balance between glioma cells and tumor microenvironment after irradiation.

Malignant gliomas invariably recur after irradiation, showing radioresistance. Meanwhile, cranial irradiation can bring some risk for developing cognitive dysfunction. There is increasing evidence that cytokines play their peculiar roles in these processes. On the one hand, cytokines directly influence the progression of malignant glioma, promoting or suppressing tumor progression. On the other hand, cytokines indirectly contribute to the immunologic response against gliomas, exhibiting pro-inflammatory or immunosuppressive activities. We propose that cytokines are not simply unregulated products from tumor cells or immune cells, but mediators finely adjust the balance between glioma cells and tumor microenvironment after irradiation. The paper, therefore, focuses on the changes of cytokines after irradiation, analyzing how these mediate the response of tumor cells and normal cells to irradiation. In addition, cytokine-based immunotherapeutic strategies, accompanied with irradiation, for the treatment of gliomas are also discussed.

Irradiation enhances expression of cxcr4 in murine glioma cells via HIF-1α-independent pathway.

OBJECTIVE: To investigate levels of chemokine (C-X-C motif) receptor 4 (cxcr4) mRNA and protein in X-irradiated glioma cells. METHODS: Murine malignant glioma GL261 cells transfected with hypoxia-inducible factor (HIF)-1α miRNA or control miRNA were irradiated with X-radiation. Cxcr4 mRNA and protein were analysed using real-time reverse transcription-polymerase chain reaction and Western blot, respectively. RESULTS: Levels of cxcr4 protein in GL261 cells increased in a radiation dose-dependent manner 48 h after 0, 5, 10 and 15 Gy X-irradiation. Irradiation of both HIF-1α knockdown cells and control cells resulted in a significant increase in cxcr4 mRNA levels, compared with nonirradiated cells, at 24 h after 5 Gy X-irradiation. CONCLUSION: Irradiation enhances expression of cxcr4 in glioma cells via a HIF-1α-independent pathway.

A novel electrochemical method to detect cell surface carbohydrates and target cells.

Glycosylation of cell surfaces is a critical factor in many biological processes; however, the lack of effective analytical tools for the detection of cell surface carbohydrates has been the bottleneck for probing into the processes. In this paper, a novel electrochemical method is presented for the analysis of cell surface carbohydrates, which can be also used to detect the target cells. Firstly, 5-hydroxy-3-hexanedithiol-1,4-naphthoquinone (JUG(thio)), the electrochemical reporter, and anti-selectin aptamer are successively modified onto the surface of a gold electrode. Different concentrations of intestinal human colon adenocarcinoma (LS180) cells are employed as the target cells for this study. Consequently, the specific carbohydrates on the surfaces of LS180 cells and anti-selectin aptamers will compete for combination with selectin in the system. As a result, the oxidation signal of JUG(thio) is changed and the detection of the cell surface carbohydrates can be achieved easily and sensitively. Furthermore, the proposed method can be used to specifically detect LS180 cells in a wide concentration range, from 10(3) to 10(7) cells/mL, with a good linear relationship and low detection limit, which might be promising for the diagnosis of cancer and some other diseases in the future.

[Efficacy observation of accelerated hyperfractionation recourse radiotherapy plus concurrent capecitabine in the treatment of locoregional recurrent rectal cancer].

OBJECTIVE: To evaluate the efficacy of accelerated hyperfractionation (CAF) radiotherapy plus concurrent capecitabine in the treatment of locoregional recurrent rectal cancer. METHODS: Between June 2004 and January 2008, 53 patients with locoregional recurrent rectal cancer were treated with CAF 1.2 Gy/f, 2 f/d plus concurrent capecitabine at an oral dosage of 825 mg/m2 bid on each day of radiotherapy period. The first daily dose was applied at 2 h pre-irradiation, d1-14 and d22-35. After a regimen of 36 Gy/30 f/3 w, the feasibility of surgical resection was then evaluated by CT. Patients unsuitable for surgical resection continued CAF. And the total dose was 52.8-57.6 Gy. RESULTS: The complete response rate was 9.8%, the partial response rate 45.1%, the effective rate 54.9%, the no-change rate 29.4%, the progression rate 15.7%, the surgical resection rate 23.5% and the R0, R1 resection rates 21.6% and 1.9% respectively. The Time to Progression was 10.5 months, 1-year survival rate was 84.3%, 2-year survival rate was 61.1%. Quality of life improved in treatment group. Toxic and adverse effects were gastrointestinal and hematological toxicities. There was no treatment-related mortality. CONCLUSION: The 3-dimensional conformal radiotherapy plus concurrent chemotherapy may be an effective and well-tolerated regimen in patients with postoperative locoregional recurrent or metastatic rectal cancer.

[Efficacy of oxaliplatin plus 5-fluorouracil/leucovorin calcium combined with concurrent radiotherapy for local advanced gastric cancer].

OBJECTIVE: To evaluate the efficacy of r oxaliplatin plus 5-fluorouracil/leucovorin calcium (LV) combined with concurrent radiotherapy in the treatment of local advanced gastric cancer. METHODS: 83 patients with local advanced gastric cancer were randomized into 2 groups. Group I (n = 40) underwent irradiation at the dose of 40 - 45 Gy 5 times a week on the primary tumor and the lymph nodes with the size > or = 10 mm in short axis, and receiving intravenous drip of OXA 85 mg/m2 for 2 h, intravenous injection of LV 200 mg/m2, and then intravenous injection of 5-fu 300 mg/m2, followed by continuous intravenous infusion of 5-fu 500 mg/m2, for 22 h, with 2 weeks as a cycle. Three cycles of chemotherapy were given during the radiotherapy. Then operative evaluation was conducted. Those resectable underwent operation and then 3 cycles of adjuvant chemotherapy. Those un-resectable underwent continuous 3 cycles of chemotherapy. Group II (n = 43) received only chemotherapy. The treatment was repeated until disease progression or prohibitive toxicity. RESULTS: 38 patients were evaluated in Group I, the result showed complete remission (CR) in 4 patients (10.5%), partial remission (PR) in 23(60.5%), no-change (NC) in 7(18.4%), progressive disease (PD) in 5(13.2%), with the remission rate (RR) of 71% (27/40). 42 patients were evaluated in Group II, the result showed CR in 3 patients (7.14%), PR in 16(14.3%), NC in 13(30.9%), and PD in 9(26.2%)with the RR of 45% (19/43). The resection rates of Groups I and II were 32.5% and 27.9% respectively (P = 0.649). The R0 resection rates of Groups I and II were 77.8% and 57.1% respectively (P = 0.161). The mean survival times of the resectable patients in Groups I and II were 45 months and 28 months respectively, and the 2-year overall survival (OS) of the resectable patients in Groups I and II were 65.8% and 56.3% respectively (P = 0.371). The mean survival times of the un-resectable patients in Groups I and II were 14 months and 9 months respectively, and the 2-year OS rates of the un-resectable patients in Groups I and II were 28.3% and 20.7% respectively (P = 0.017). The toxic and adverse effects included gastrointestinal and hematological toxicity. There was no treatment-related death. CONCLUSION: Radiotherapy combined with concurrent chemotherapy may be an effective and well-tolerated regimen in patients with advanced and metastatic gastric cancer.

[Combination of docetaxel and capecitabine for the treatment of anthracycline-resistant advanced breast carcinoma].

OBJECTIVE: To evaluate the efficacy and toxicity of docetaxel and capecitabine combination in the treatment of anthracycline-resistant advanced breast carcinoma. METHODS: Forty-three patients with anthracycline-resistant advanced breast carcinoma were treated with docetaxel combined with capecitabine between January 2002 and November 2004. Docetaxel was administered intravenously at a dose of 75 mg/m(2) on D1, and oral intake of capecitabine at a dose of 1600 mg/d on D1 to D14, every 21 days as a cycle. The median number of cycles was 4 (range, 4 approximately 6 cycles). RESULTS: All the 43 patients had a mean follow-up of 15 months. The overall response rate was 62.8%, with a complete response rate of 20.9% and partial response rate of 44.2%. The median survival time was 15 months with a median time to progression of 7.5 months. The one-year and 2-year survival rates were 62.8% and 41.9%, respectively. The quality of life was improved in all patients. The major toxicity and adverse effects were gastrointestinal reaction and hematological toxicity. CONCLUSION: The combination of docetaxel and capecitabine for the treatment of anthracycline-resistant advanced breast carcinoma is effective, safe and tolerable.