Chimeric antigen receptor T cell targeting EGFRvIII for metastatic lung cancer therapy / 医学前沿

Lung cancer is the most common incident cancer and the leading cause of cancer death. In recent years, the development of tumor immunotherapy especially chimeric antigen receptor T (CAR-T) cell has shown a promising future. Epidermal growth factor receptor variant III (EGFRvIII) is a tumor-specific mutation expressed in various types of tumors and has been detected in non-small cell lung cancer with a mutation rate of 10%. Thus, EGFRvIII is a potential antigen for targeted lung cancer therapy. In this study, CAR vectors were constructed and transfected into virus-packaging cells. Then, activated T cells were infected with retrovirus harvested from stable virus-producing single clone cell lines. CAR expression on the surfaces of the T cells was detected by flow cytometry and Western blot. The function of CAR-T targeting EGFRvIII was then evaluated. The EGFRvIII-CAR vector was successfully constructed and confirmed by DNA sequencing. A stable virus-producing cell line was produced from a single clone by limited dilution. The culture conditions for the cell line, including cell density, temperature, and culture medium were optimized. After infection with retrovirus, CAR was expressed on more than 90% of the T cells. The proliferation of CAR-T cells were induced by cytokine and specific antigen in vitro. More importantly, EGFRvIII-CART specifically and efficiently recognized and killed A549-EGFRvIII cells with an effector/target ratio of 10:1 by expressing and releasing cytokines, including perforin, granzyme B, IFN-γ, and TNF-α. The in vivo study indicated that the metastasis of A549-EGFRvIII cells in mice were inhibited by EGFRvIII-CART cells, and the survival of the mice was significantly prolonged with no serious side effects. EGFRvIII-CART showed significantly efficient antitumor activity against lung cancer cells expressing EGFRvIII in vivo and in vitro. Therefore, CAR-T targeting EGFRvIII is a potential therapeutic strategy in preventing recurrence and metastasis of lung cancer after surgery.

Adoptive cell transfer therapy for hepatocellular carcinoma / 医学前沿

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. This malignancy is associated with poor prognosis and high mortality. Novel approaches for prolonging the overall survival of patients with advanced HCC are urgently needed. The antitumor activities of adoptive cell transfer therapy (ACT), such as strategies based on tumor-infiltrating lymphocytes and cytokine-induced killer cells, are more effective than those of traditional strategies. Currently, chimeric antigen receptor T-cell (CAR-T) immunotherapy has achieved numerous breakthroughs in the treatment of hematological malignancies, including relapsed or refractory lymphoblastic leukemia and refractory large B-cell lymphoma. Nevertheless, this approach only provides a modest benefit in the treatment of solid tumors. The clinical results of CAR-T immunotherapy for HCC that could be obtained at present are limited. Some published studies have demonstrated that CAR-T could inhibit tumor growth and cause severe side effects. In this review, we summarized the current application of ACT, the challenges encountered by CAR-T technology in HCC treatment, and some possible strategies for the future direction of immunotherapeutic research.

Impacts of early metoprolol intervention on connexin 43 and phosphorylated connexin 43 expression in rabbits with experimental myocardial infarction / 中华心血管病杂志

Objective@#To investigate the early intervention effects of metoprolol on connexin 43(Cx43) and phosphorylated Cx43 (p-Cx43) expression in rabbits with post myocardial infarction.@*Methods@#A total of 24 adult male New Zealand white rabbits were divided into sham group (n=6), early treatment group(n=6), routine treatment group(n=6), and myocardial infarction group(n=6) with a randomized block design blocked by weight. Myocardial infarction was induced by left anterior descending coronary artery (LAD) ligation. Rabbits in sham group received similar surgical procedure without LAD ligation. Metoprolol (12.5 mg/kg dissolved in 2 ml distilled water) was applied to rabbits in early treatment group and routine treatment group per gavage immediately after recovery from anesthesia and at 24 hours after myocardial infarction, respectively, then treated daily for 40 days. Rabbits in sham group and myocardial infarction group received 2 ml distilled water per gavage daily for 40 days. Plasma lactate dehydrogenase (LDH) and creatine kinase (CK) level were detected by automatic biochemistry analyzer after 6 hours in all rabbits. Ventricular fibrillation threshold (VFT) was measured in vivo by bipolar pacing electrodes at 40 days. Cx43 and p-Cx43 distribution in ventricular tissue was detected by immunofluorescence analyses. Cx43 and p-Cx43 protein level in ventricular tissue was determined by Western blot.@*Results@#(1) Plasma LDH ((851.7±85.9)U/L vs. (332.3±39.6)U/L, P<0.01) and CK ((1 192.7±105.3)U/L vs. (462.3±65.6)U/L, P<0.01) were significantly higher in myocardial infarction group than in sham group (both P<0.01). (2) VFT was significantly lower in myocardial infarction group than that in sham group ((470.0±91.0) beats per minute vs. (683.3±60.9) beats per minute, P<0.05), and VFT was significantly higher in early treatment group ((633.3±43.2) beats per minute) and routine treatment group ((645.0±30.8) beats per minute) than in the myocardial infarction group (both P<0.05). (3) Immunofluorescence analyses showed that Cx43 was mainly localized in the intercalated disk, which was perpendicular to the cell long axis with linear arrangement, and less lateral distribution in sham group, early treatment group and routine treatment group, which was significantly different as the case in the myocardial infarction group. The expression of p-Cx43 in myocardial infarction group was less than in sham group, which was significantly upregulated in in early treatment group and routine treatment group when compared with myocardial infarction group, and expression of p-Cx43 was significantly higher in early treatment group than in routine treatment group. (4)The p-Cx43/Cx43 ratio of protein was significantly lower in myocardial infarction group than in sham group (0.165±0.011 vs. 0.363±0.046, P<0.05), and significantly higher in early treatment group (0.720±0.063) and routine treatment group (0.364±0.030) than in myocardial infarction group (both P<0.05), and this ratio was significantly higher in early treatment group than in routine treatment group (P<0.05).@*Conclusion@#Metoprolol treatment, especially the early metoprolol treatment (within 24 hours after LAD ligation), could significantly improve VFT by ameliorating the distribution and dephosphorylation of myocardial Cx43 in rabbits with experimental myocardial infarction.

Teaching evaluation of applying article structure analysis to improve medical graduate students' ability to read research articles / 中华医学教育探索杂志

Objective To evaluate the teaching effectiveness of applying article structure analysis to improve medical graduate students' ability to read research articles.Methods 48 medical graduate students from basic medicine school of the Fourth Military Medical University were randomly and equally divided into the experimental group and control group.In the reading ability training of scientific research papers,the experimental group used the teaching of the structure analysis,while the control group used the collective self study.Before and after the training,the two groups of students were implemented a unified reading ability test and self reading ability evaluation survey,and after the training,the teaching satisfaction survey was conducted among the experimental group only.SPSS 16 was used to analyze the correlation data and Wilcoxon for signed-rank t est.Results After training the reading ability test results showed that reading ability score (P=0.013),consumed reading time score (P=0.003) and reading efficiency (P=0.004) of the experimental group were significantly higher than those of control group.The two groups of students' self-evaluation of the reading ability showed that after training,the scores of the students in the experimental group were higher than those in the control group,and the differences were statistically significant (P values were less than 0.05).The experimental group students' teaching satisfaction survey to article structure analysis showed students' score in 6 survey contents were greater than 3,namely degree of evaluation was more than general,among which,the score of four survey contents was more than 4,that is to achieve satisfied or very satisfied.Conclttsion Applying article structure analysis can significantly improve medical graduate students' ability to read research articles.

Analysis of the effect and safety of transradial percutaneous coronary intervention / 心血管康复医学杂志

Objective:To study the effect and safety of transradial percutaneous coronary intervention (PCI).Meth-ods:Clinical data of 306 patients,who received PCI in our hospital from Mar 2012 to Jan 2014,were retrospectively analyzed,including radial group (n=153),and femoral group (n=153).Therapeutic effect,time and postoperative complications etc.were compared between two groups.Results:A total of 151 cases completed PCI successfully in radial group,the success rate was 98.7%;a total of 150 cases completed PCI successfully in femoral group,the suc-cess rate was 98.0%,there was no significant difference in success rate of operation between two groups,P >0.05. Compared with femoral group,there were significant reductions in hospitalization time [(8.0±3.5)d vs.(3.5± 1.7)d],treatment cost [(3.74±2.06) × 104 yuan vs.(2.61 ± 1.4) × 104 yuan],P <0.01 both,in incidence rates of postoperative coronary occlusion (3.92% vs.0%),arrhythmia (11.76% vs.1.31%),vascular spasm (6.54% vs.1.96%)and hematoma (7.19% vs.0.65%)etc.in radial group,P < 0.05 or < 0.01. Conclusion:Transradial PCI possesses better effect than that of transfemoral ,and it can reduce hospitalization time,cost and postoperative complications,which is worth extending.

Influence of long-term oral valsartan on ventricular arrhythmia after myocardial infarction in rabbits / 心血管康复医学杂志

Objective: To explore influence of long-term oral valsartan-angiotensin II type 1 receptor blocker on ventricular arrhythmia after myocardial infarction (MI) in rabbits and its possible mechanism. Methods: A total of 24 New Zealand rabbits were randomly divided into sham operation group (n=8), MI group (n=8) and valsartan group (n=8) according to number table. Sham operation group only received thoracotomy without ligation of anterior descending branch of left coronary artery (LAD), while MI group and valsartan group received ligation of anterior descending branch of LAD. Valsartan group received valsartan gavage (10 mg•kg-1•d-1) since the second day after operation, three groups all were fed for 12 weeks. Mono active potential (MAP) of left ventricular myocardial cells of subendocardial myocardium（inner layer myocardium）, subepicardial myocardium（outer layer myocardium）and middle layer myocardium were recorded before MI and 12 weeks after MI, and times of provocative malignant arrhythmias were recorded on 12 weeks after MI in three groups. Results: 1. Ventricular tachycardia or fibrillation (VT/ VF) episodes were markedly decreased in VAL group than that in MI group on 12 weeks after MI [(3.1±0.8) vs. (12.7±1.5), P＜0.05]; 2. After MI 12 w, the action potential duration to 90% repolarization (APD90) of three-layer ventricular myocytes in MI group was prolonged than that before MI [（259.2±22.1）ms,（288.0±25.8）ms,（244.6±22.6）ms vs.（230.1±23.2）ms,（244.2±23.4）ms,（229.0±21.7）ms, P＜0.05 or＜0.01]；but there were no significant difference in APD90 of three layers ventricular myocytes between before and after MI in valsartan group (P>0.05 all); Compared with sham operation group and valsartan group, there was significant prolonged in transmural dispersion of repolarization (TDR) [(18.8±6.2) vs. (23.9±7.7) vs. (37.2±10.2), P0.05). Conclusions: Long-term oral valsartan can significantly reduce malignant ventricular arrhythmia incidence in rabbits after MI, which may be related to improving TDR in rabbits after MI.

Variation in serum visfatin levels 24 hours after coronary stent implantation / 中国组织工程研究

BACKGROUND:Coronary stent implantation can cause blood vessel damage and wal reconstruction, leading to vascular stent restenosis. Studies have found that visfatin is associated with inflammatory reaction, and exhibits an increased expression at the site of plaque rupture in acute myocardial infarction. OBJECTIVE:To investigate the influence of percutaneous coronary intervention on the levels of visfatin in patients with coronary heart disease. METHODS:Thirty patients with acute myocardial infarction within 12 hours after the onset of the chest pain, 30 patients with unstable pectoris and 30 patients with stable angina pectoris were included. Al patients were successfuly treated by percutaneous coronary intervention. Meanwhile, 30 patients only undergoing coronary angiography but not stenting treatment were selected, and another 30 patients without any treatment served as normal control group. RESULTS AND CONCLUSION:According to enzyme-linked immunosorbent method, the visfatin levels of acute myocardial infarction, unstable angina, stable angina and coronary angiography groups continue to rise at pre-operation, 30 minutes, 6 hours, 12 hours, 24 hours after operation, al of which were higher than that in the normal control group (P < 0.05). The results confirmed that within 24 hours after coronary stent implantation the visfatin levels continue to rise.

Biological distribution of 131I-HAb18F(ab')2 in patients with hepatocellular carcinoma / 生物医学工程学杂志

Before 131I-HAb18F(ab')2 administration, 24 cases of mid-term or advanced hepatocellular carcinoma(HCC) were given Lugol's Liquid to block the thyroid gland, and submitted to hepatic colloid imaging. The cases were randomly divided into 3 groups. Then 131I-HAb18F(ab')2 was injected into the target hepatic artery with doses of 0.5, 0.75, 1.0 mCi/kg, respectively. At the followed 10, 48, 96 and 192 hours, 131I-HAb18F(ab')2 distribution in human body was acquired by whole body dynamic image with Single photon emission computed tomography(SPECT). The results showsed that 131I-HAb18F(ab')2 in tumor tissue was significantly higher than that in normal liver tissue and other organs. This difference became obvious as time passed. 131I-HAb18F(ab')2 is stable in human body and it can combine with HCC tissue specifically. So it is a new medicine deserving further research for the treatment of HCC.

The Anti-Hepatoma Effect of Superantigen Staphylococcal Enterotoxin A Targeted by Monoclonal Antibody / 中国肿瘤生物治疗杂志

Objective: To prepare the conjugate of supcrantigen (SAg) staphylococcal enterotoxin A (SEA) and monoclonal antibody (McAb) against human hepatocellular carcinoma HAbl8 F(ab' )_(2) fragment and to investigate the anti-human hepatoma effect of peripheral blood mononuclear cells (PBMC) targeted by HAbl8 F(ab' )i-SEA. Methods: McAb HAbl8 was extracted and its F(ab' )_(2) fragment was prepared with papain; the conjugate HAblS F(ab' )_(2)-SEA was prepared with N-succinimidyl-3-(2-pyridyldithio) propionate (SPDP); eveny collected peak after purification was identified with gel chromatography; the activity of antibody in the conjugate was identified with immunohistocheinical ABC method; the anti-hepatoma effect of PBMC targeted by HAbl8 F(ab' )_(2)-SEA was observed with MTT method. Results: The conjugate HAbl8 F(ab' )_(2)-SEA was prepared successfully and it had obvious effect of targeting PBMC to kill hepatoma cells, and this effect is correlated positively with the dose of HAbl8 F(ab')_(2)-SEA. Control groups had no such effect. Conclusion: Targeting therapy of hepatoma with McAb-SAg conjugate might be a kind of hopeful model of hepatoma im-munotherapy.

The Quality Control and Targeting Studies of Anti-hepatoma Monoclonal Antibodies / 中国肿瘤生物治疗杂志

The cell suspensions prepared from surgically resected hepatoma specimens were used to immunize BALB/c mice and, with the hybridoma technique, a battery of high affinity monoclonal anti-hepatoma antibodies were obtained which were designated HAbl8, Fll, E5 and A10 separately. Immunohistochimical staining showed that the above 4 antibodies possessed good selective reactivity with hepatoma tissue. After radioiodination of Fll, E5, A10, HAbl8 IgG and It's F(ab')_(2) fragments, the labelled reagents were employed for radioimmunoimaging in hepatoma-bearing nude mice and the in vivo detection appeared promising, with tumor/non-tumor ratios being 6.88, 5.14, 5.67, 5.15 and 14.47 respectively. The in vivo localization ablities of the antibodies seemed better compared to other similar findings published elswhere (Dunk AA, 1987). Also, ~(131) I -HAbl8 I gG and its radiolabelled fragments were utilized for radioimmunotherapy in hepatoma-bearing nude mice, with complete response rate and partial response rate being 42%(5/12) and 50% (6/12)respectively. When the HAbl8 conjugate with radioiodine was introduced for the in vivo imaging in hepatoma patients, a positivity rate of 86.5% (45/52)was witnessed, with the smallest tumor foci detected being only 0.5cm in diameter. In the in vivo targeting therapy with the immunoconjugate, a partial response rate of 69.6% (16/23) was obtained. In summary, the antibodies reported here have lended a novel regime for the present comprehensive therapy protocol of hepatoma.

Cloning and Identification of Fd and Light Chain Genes of MAb HAb18 against Human Hepatoma / 中国肿瘤生物治疗杂志

Objective: To clone Fd and light chain genes of monoclonal antibody HAb18 against human hepatoma and verify their accuracy and liability. Methods: Total RNA was extracted from hybridoma cell line secreting MAb HAb18, and Fd and light chain genes were amplified by RT-PCR. After PCR products were ligated into pMD18T vector, positive clones were screened and DNA sequences were tested and analysed by relative softwares. Then, light chain and Fd genes were sequential cloned into phage display vector pComb3. After recombinant vector was transformed into E.coli XL1-blue, recombinant vector was rescued by helper phage M13K07 and the specificity of phages to antigen was detected by indirect ELISA. Results: The size of amplified Fd and light chain genes was separately 665 bp and 668 bp. The results of sequence analysis showed that both VL and VH contained 2 characteristic cystines and CH1 was IgG1 classes and CL was ?. ELISA result identified that expressed Fab antibody could specially bind to corresponding antigen. Conclusion: Fd and light chain genes of MAb HAb18 were successfully cloned, which lay a good foundation for constructing a diversity of engineering antibody.

The Screening of Human Anti-Hepatoma Fd Fragments Guided with the Chemeric Light Chain of HAb18 / 中国肿瘤生物治疗杂志

Objective: To select anti-HAb18G (hepatoma associated antigen) human Fd fragments with guided selection of L chain of chimeric Fab-HAb18. Methods: The human Fd repertories genes were amplified by RT-PCR from PBMC of hepatoma patients, and cloned into the vector pComb3X with chimeric L chain to construct the human-mouse hybrid Fab phage library. HAblSGE, extracellular region of HAblSG, was used as antigen to screen. The positive clones was obtained by ELISA and FCM with p Ⅲ-fusion Fab antibody. The DNA sequences were analyzed. Results: A human-mouse Fab antibody library were constructed with 2?107 PFU. After 6 rounds panning, 7 positive clones were obtained with ELISA and FCM. And sequences of 2 clones with better affinity were same. The CHI belonged to the IgG2 class as the parent Fd, and the variable region belonged to VH3 family. Conclusions: Through the construction of the HuMFab phage antibody library and chemeric L chain-guided selection, we get the available human Fd fragments for subsequent research.