Objective To improve the gene targeting efficiency with C57BL/6 embryonic stem ( ES) cells.Meth-ods Three different genetically modified C57BL/6 ES cell lines, named TLX3, Ai3K and SL, were microinjected into ICR, B6( Cg)-Tyrc-2J and BALB/c mouse blastocysts, respectively.The efficiency was statistically evaluated according to three aspects:blastocyst collection, chimera production and germline transmission.Results None of the three ES cell lines was germline transmitted with B6(Cg)-Tyrc-2J mice as blastocyst donors, while it was achieved with both BALB/c and ICR mouse blastocysts.Compared in the aspect of blastocysts collection, ICR mouse was much better than BALB/c mouse (P<0.05), and the chimera production efficiency of ICR mouse was comparable to that of BALB/c mouse (P =0.115). As to the germline transmission efficiency, that of BALB/c mice is significantly higher than that of the ICR mice ( P<0.01).Conclusions The germline transmission efficiency of BALB/c mouse is highest among these three mouse strains. However, it has the disadvantages of blastocyst collection, developmental delay and zona pellucida fragility, compared with ICR mouse.Therefore, ICR mouse is also a good candidate as blastocyst donor for embryonic stem cell microinjection.

Objective To establish a simple , fast and economic total DNA extraction method to serve the rapid identification of model mouse genotype in large number of mice .Methods Three methods, i.e.phenol extraction, isopropyl alcohol precipitation and mouse ear boiling methods were used to extract the total DNA from ten C 57-rasmodel mice.The purity and yield of DNA obtained by the three methods were compared , and polymerase chain reaction ( PCR) assay was used to compare the efficacy of the three extraction methods .Results Among the three methods , phenol extraction was the best and isopropyl alcohol precipitation was the poorest in DNA yield .In terms of DNA purity , the phenol extraction was the best and the mouse ear boiling method was the poorest .All the three methods could be used to extract the total DNA from mice serving as template of PCR reaction for the mouse genotype identification .The time consumption of three methods are 12.5 hr ,13 hr and 0.18 hr.Mouse ear boiling method was significantly lower than that of the other two methods ( P <0.01 ) ,.The obtained total DNA can be stored at conventional -20℃for 7 days and 30 days later still can be used as a template for PCR reaction .Conclusions Among the three methods studied , the mouse ear boiling method is simple and with the lowest cost , so it is feasible for total DNA extraction in scaled genotyping experiments .

Objective To obtain the basic growth parameters of a self-established F1 hybrid CB6F1 C57-ras transgenic mouse model, and to provide basic information for commercialization of this mouse model. Methods F1 hybrid mice (CB6F1) were produced by crossing C57-ras heterozygous transgenic (c-Ha-ras+/-) male mice and wild-type BALB/cJ female mice.The average litter size, weaning rate, sex ratio, growth performance and C57-ras transgenic positive rate were recorded and analyzed.Results The average litter size was eight, weaning rate was 90%, and sex ratio was approximately in accordance with prediction.The average body weight of newborn mice was 1.73 ±0.05 g.The average body weight of 10-week old c-Ha-ras transgenic female and male mice in CB6F1 background was 24.38 ±1.74 g and 29.42 ±1.72g, respectively, which had a significant difference (P<0.01).The c-Ha-ras transgenic positive rate was 46.9%. which was in accordance with genetic rules.Conclusions The F1 hybrid mice (CB6F1) produced by crossing C57-ras heterozygous transgenic ( c-Ha-ras +/-) male mice and wild-type BALB/cJ female mice show normal growth performance and development characteristics, and it can be used for large-scale commercial supply.

Strategies in comprehensive therapy for gastrointestinal (GI) cancer have been optimized in the last decades to improve patients' outcomes. However, treatment options remain limited for late-stage or refractory diseases. The efficacy of immune checkpoint inhibitors (ICIs) for treatment of refractory GI cancer has been confirmed by randomized clinical trials. In 2017, pembrolizumab was approved by the US Food and Drug Administration as the first agent for treatment of metastatic solid tumors with mismatch repair deficiency, especially for colorectal cancer. Given the different mechanisms, oncologists have focused on determining whether ICIs-based combination strategies could achieve higher efficacy than conventional therapy alone in late-stage or even front-line treatment of GI cancer. This review discusses the current status of combining immune checkpoint inhibitors with molecular targeted therapy, chemotherapy, or radiotherapy in GI cancer in terms of mechanisms, safety, and efficacy to provide basis for future research.
Combined Modality Therapy ; methods ; Gastrointestinal Neoplasms ; immunology ; therapy ; Humans ; Immunotherapy ; methods ; trends ; Randomized Controlled Trials as Topic

Objective To determine the influence of abiraterone acetate (AA) on neuroendocrine differentiation (NED) in metastatic castration-resistant prostate cancer (mCRPC) and the prognostic predicting value of the serum NED markers in mCRPC patients treated with AA.Methods We conducted an analysis in 115 chemotherapy-naive mCRPC patients who were treated with chemotherapy in Renji hospital from 2013 to 2017.The median age was 70,ranged from 65 to 76 years old.The median CgA,NSE and PSA levels were 101.1 ng/ml (78.5-150.0 ng/ml),13.4 ng/ml (10.5-17.6 ng/ml) and 38.8 ng/ml (11.2-123.2 ng/ml),respectively.Among them,48 cases were classified as the group without AA treatment.The other 67 cases were classified as group after AA failure.In group without AA treatment,the median CgA,NSE and PSA levels were 109.1 ng/ml(80-151.5 ng/ml);13.8 ng/ml(10.8-18.2 ng/ml) and 39.2 ng/ml (8.6-200 ng/ml),respectively.In group after AA failure,the median CgA,NSE and PSA levels were 105.4 ng/ml(78.8-175.5 ng/ml),13.8 ng/ml(10.8-17.6 ng/ml) and 39.0 ng/ml(8.4-219.8 ng/ml),respectively.In the group with serial evaluation of NED markers during AA treatment,the median serum CgA,NSE levels at baseline were 115.9 ng/ml(90.1-201.5 ng/ml),13.3 ng/ml (10.4-18.1 ng/ml),respectively.The endpoints were PSA PFS(progression-free survival) and radiographic PFS (rPFS).Results In 34 patients with serial evaluation,serum NED markers level in 19 patients increased after the failure of AA treatment.Median serum CgA and NSE levels were 115.9 ng/ml(90.1-201.5 ng/ml)and 13.25 ng/ml (10.37-18.14 ng/ml) at baseline.Median serum CgA and NSE levels were 129.6ng/ml (75.5-230.5 ng/ml) and 14.7 ng/ml (11.8-19.1 ng/ml) after 6 months treatment,respectively.The median serum CgA and NSE levels were 130.4 ng/ml (95.7-205.7 ng/ml) and 15.2 ng/ml(12.4-18.7 ng/ml) at the time of failure of AA treatment,respectively.There was no significant difference of NED markers between baseline and failure of AA treatment (P =0.243).In logistic univariate analysis,AA treatment and its duration were not independent factors influencing NED(P =0.30;P =0.52).Compared with the NED markers elevation group in the first 6 months of AA treatment and baseline supranormal NED markers group,the NED markers decline group(PSA PFS(17.1 vs.10.4 months,P ＜ 0.001) and rPFS (17.0 vs.10.4 months,P =0.003)) and baseline normal NED markers group(PSA PFS(14.1 vs.9.5 months,P =0.001) and rPFS(16.4 vs.10.5 months,P ＜ 0.001)) has a longer median PSA PFS and rPFS respectively.In multivariate Cox analysis,baseline NED markers level and NED markers variation during the first 6 months of AA treatment remained significant predictors of rPFS(P ＜ 0.05),and PSA-PFS (P ＜ 0.05).Conclusions We found there was heterogeneity in changes of NED markers in different mCRPC patients during AA treatment,and AA might not significantly lead to progression of NED of mCRPC in general.Serial CgA and NSE evaluation might help clinicians guide clinical treatment of mCRPC patients.Serum NED markers elevation during the first 6 months of AA treatment and elevated baseline NED markers levels indicated poor prognosis in mCRPC treated with AA.

Fibrosis is one of the key factors that lead to the immune exclusion of solid tumors. Although degradation of fiber is a promising strategy, its application was still bottlenecked by the side effects of causing metastasis, resulting in the failure of immunotherapy. Here, we developed an antimetastatic polymer (HPA) for the delivery of chemo-drug and antifibrotic siPAI-1 to form the nano-permeator. Nano-permeator shrank after protonation and deeply penetrated into the tumor core to down-regulate the expression of PAI-1 for antifibrosis, and further promoted the sustained infiltration and activation of T cells for killing tumor cells. Moreover, metastasis after fiber elimination was prevented by multivalent CXCR4 antagonistic HPA to reduce the attraction of CXCL12 secreted by distant organs. The administration of stroma-alleviated immunotherapy increased the infiltration of CD8⁺ T cells to 52.5% in tumor tissues, inhibiting nearly 90% metastasis by HPA in distant organs. The nano-permeator reveals the mechanism and correlation between antifibrosis and antimetastasis and was believed to be the optimizing immunotherapy for solid fibrotic tumors.