Prognostic value of preoperative carcinoembryonic antigen/tumor size in rectal cancer

BACKGROUND Carcinoembryonic antigen(CEA)is a commonly used biomarker in colorectal cancer.However,controversy exists regarding the insufficient prognostic value of preoperative serum CEA alone in rectal cancer.Here,we combined preoperative serum CEA and the maximum tumor diameter to correct the CEA level,which may better reflect the malignancy of rectal cancer.AIM To assess the prognostic impact of preoperative CEA/tumor size in rectal cancer.METHODS We retrospectively reviewed 696 stage I to III rectal cancer patients who underwent curative tumor resection from 2007 to 2012.These patients were randomly divided into two cohorts for cross-validation:training cohort and validation cohort.The training cohort was used to generate an optimal cutoff point and the validation cohort was used to further validate the model.Maximally selected rank statistics were used to identify the optimum cutoff for CEA/tumor size.The Kaplan-Meier method and log-rank test were used to plot the survival curve and to compare the survival data.Univariate and multivariate Cox regression analyses were used to determine the prognostic value of CEA/tumor size.The primary and secondary outcomes were overall survival(OS)and disease-free survival(DFS),respectively.RESULTS In all,556 patients who satisfied both the inclusion and exclusion criteria were included and randomly divided into the training cohort(2/3 of 556,n=371)and the validation cohort(1/3 of 556,n=185).The cutoff was 2.429 ng/mL per cm.Comparison of the baseline data showed that high CEA/tumor size was correlated with older age,high TNM stage,the presence of perineural invasion,high CEA,and high carbohydrate antigen 19-9(CA 19-9).Kaplan-Meier curves showed a manifest reduction in 5-year OS(training cohort:56.7%vs 81.1%,P<0.001;validation cohort:58.8%vs 85.6%,P<0.001)and DFS(training cohort:52.5%vs 71.9%,P=0.02;validation cohort:50.3%vs 79.3%,P=0.002)in the high CEA/tumor size group compared with the low CEA/tumor size group.Univariate and multivariate analyses identified CEA/tumor size as an independent prognostic factor for OS(training cohort:hazard ratio(HR)=2.18,95%confidence interval(CI):1.28-3.73,P=0.004;validation cohort:HR=4.83,95%CI:2.21-10.52,P<0.001)as well as DFS(training cohort:HR=1.47,95%CI:0.93-2.33,P=0.096;validation cohort:HR=2.61,95%CI:1.38-4.95,P=0.003).CONCLUSION Preoperative CEA/tumor size is an independent prognostic factor for patients with stage I-III rectal cancer.Higher CEA/tumor size is associated with worse OS and DFS.

Colorectal cancer vaccines: Tumor-associated antigens vs neoantigens

Therapeutic options for the treatment of colorectal cancer(CRC) are diverse but still not always satisfying. Recent success of immune checkpoint inhibition treatment for the subgroup of CRC patients suffering from hypermutated tumors suggests a permanent role of immune therapy in the clinical management of CRC. Substantial improvement in treatment outcome could be achieved by development of efficient patient-individual CRC vaccination strategies. This mini-review summarizes the current knowledge on the two general classes of targets: tumor-associated antigens(TAAs) and tumorspecific antigens. TAAs like carcinoembryonic antigen and melanoma associated antigen are present in and shared by a subgroup of patients and a variety of clinical studies examined the efficacy of different TAA-derived peptide vaccines. Combinations of several TAAs as the next step and the development of personalized TAA-based peptide vaccines are discussed. Improvements of peptidebased vaccines achievable by adjuvants and immunestimulatory chemotherapeutics are highlighted. Finally, we sum up clinical studies using tumor-specific antigens-in CRC almost exclusively neoantigens-which revealed promising results; particularly no severe adverse events were reported so far. Critical progress for clinical outcomes can be expected by individualizing neoantigen-based peptide vaccines and combining them with immunestimulatory chemotherapeutics and immune checkpoint inhibitors. In light of these data and latest developments, truly personalized neoantigen-based peptide vaccines can be expected to fulfill modern precision medicine's requirements and will manifest as treatment pillar for routine clinical management of CRC.

Comparisons of voided urine cytology, nuclear matrix protein-22 and bladder tumor associated antigen tests for bladder cancer of geriatric male patients in Taiwan, China

Aim： To compare the results of bladder tumor associated antigen （BTA TRAK）, nuclear matrix protein 22 （NMP 22） and voided urine cytology （VUC） in detecting bladder cancer. Methods： A total of 135 elderly male and 50 healthy volunteers enrolled in this study were classified into three groups： （i） 93 patients with bladder cancer; （ii） 42 patients with urinary benign conditions; and （iii） 50 healthy volunteers. BTA TRAK and NMP 22 kits were used to detect bladder cancer. Voided urine cytology was used to compare the sensitivity and specificity of the screening tests. Results： The sensitivity and specificity of cytology, BTA TRAK and NMP 22 were 24% and 97%, 51% and 73%, 78% and 73%, respectively. The level of NMP 22 increased with tumor grading. The BTA TRAK kit has the lowest sensitivity among the screening tests. The NMP 22 with the best sensitivity can be an adjunct to cytology for evaluating bladder cancer. Conclusion： The NMP 22 test has a better correlation with the grading of the bladder cancer than BTA TRAK. As cytology units are typically not available in hospitals or in outpatient clinics, NMP 22 might be a promising tool for screening bladder cancer.

SIGNIFICANCE OF EXPRESS OF SOME NONHORMONAL ANTIGENS IN PANCREATIC ENDOCRINE TUMORS

Objective: To study the express of some nonhormonal antigens in pancreatic endocrine tumors. Methods: The nonhormonal antigens including Alpha subunit of human chorionic gonadotropin (α HCG), progesterone receptors (PR), 7B2, HISL 19, in normal pancreatic islets and in 52 cases of pancreatic endocrine tumors (PET) were investigated by immunohistochemistry. Results: It was found that HCG can be detected in PET but not in normal islet cells. HCG immunoreactivity was expressed by 3 of 28 (10.7%) benign PET and by 14 of 24 (58.3%) malignant PET.PR was found by 20 of 28(71.4%) benign PET and by 7 of 24 (29%) malignant PET. 7B2 was detected by 23 of 28 (82.1%) benign PET and by 13 of 24 (54.2%) malignant PET. HISL 19 was appeared by 23 of 28 benign PET and by 11 of 24 (46%) malignant PET. Golgitype persisted in 87.5% malignant tumors. Conclusion: The assay of nonhormonal antigens may be well defined the clinico pathological characteristics of PET.

New tumor-associated antigen SC6 in pancreatic cancer

AIM: To examine the concentration of a new antigen SC6 (SC6-Ag) recognized by monoclonal antibody (MAb)in patients with pancreatic cancer and other malignant or benign diseases and to understand whether SC6-Ag has any clinical significance in distinguishing pancreatic cancer from other gastrointestinal diseases.METHODS: Six hundred and ninety-five serum specimens obtained from 115 patients with pancreatic cancer, 154 patients with digestive cancer and 95patients with non-digestive cancer were used and classified in this study. Serum specimens obtained from 140 patients with benign digestive disease and 89 patients with non-benign digestive disease served as controls. Ascites was tapped from 16 pancreatic cancer patients, 19 hepatic cancer patients, 16 colonic cancer patients, 10 gastric cancer and 6 severe necrotic pancreatitis patients. The samples were quantitated by solid-phase radioimmunoassay. The cut-off values (CV)of 41, 80, and 118 U/mL were used.RESULTS: The average intra- and interassay CV detected by immunoradiometric assay of SC6-Ag was 5.4% and 8.7%, respectively. The sensitivity and specificity were 73.0% and 90.9% respectively. The levels in most malignant and benign cases were within the normal upper limit. Among the 16 pancreatic cancer cases, the concentration of SC6-Ag in ascites was over the normal range in 93.8% patients. There was no significant difference in the concentration of SC6-Ag.Decreased expression of SC6-Ag in sera was significantly related to tumor differentiation. The concentration of SC6-Ag was higher in patients before surgery than after surgery. The specificity of SC6-Ag and CA19-9 was significantly higher than that of ultrasound and computer tomography (CT) in pancreatic cancer patients. Higher positive predictive values were indicated in 92.3% SC6-Ag and 88.5% CA19-9, but lower in 73.8% ultrasound and 76.2% CT.CONCLUSION: The combined test of SC6-Ag and CA19-9 may improve the diagnostic rate of primary cancer. The detection of SC6-Ag is valuable in the diagnosis of pancreatic cancer before and after surgery.

Autoantibodies against tumor-associated antigens for detection of hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is one of the most common tumors worldwide. The survival rate after the onset of symptoms is generally less than one year for the late presentation of HCC, and reliable tools for early diagnosis are lacking. Therefore, novel biomarkers for the early detection of HCC are urgently required. Recent studies show that the abnormal release of proteins by tumor cells can elicit humoral immune responses to self-antigens called tumor-associated antigens(TAAs). The corresponding autoantibodies can be detected before the clinical diagnosis of cancer. Therefore, there is growing interest in using serum autoantibodies as cancer biomarkers. In this review, we focus on the advances in research on autoantibodies against TAAs as serum biomarker for detection of HCC, the mechanism of the production of TAAs, and the association of autoantibodies with patients' clinical characteristics.

Establishment of a Tumor-bearing Mouse Model Stably Expressing Human Tumor Antigens Survivin and MUC1 VNTRs

The eukaryotic vectors VR1012 expressing survivin or 33 tandem repeats of human mucin 1（MUC1）（VNTRs）,namely,VR1012-S and VR1012-VNTR（VNTR=variable number of tandem repeat）,were constructed by cloning survivin and VNTR genes into VR1012,respectively.The eukaryotic vector pEGFP expressing survivin and MUC1 VNTRs fusion gene pEGFP-MS was also constructed.Mouse melanoma cell line（B16） stably expressing survivin and MUC1 VNTRs（MS ＋ B16） was established by Lipofectamine-mediated transfection of pEGFP-MS into B16 cells.EGFP expression in MS ＋ B16 cells was observed using a fluorescent microscope and survivin and MUC1 VNTRs（MS） expression was confirmed by means of Western blot analysis.A syngenic graft tumor model was generated by subcutaneous injection of MS ＋ B16 cells into C57/BL6 mice and tumor size increased rapidly with time in a cell number dependent manner.After the third immunization,mice were challenged subcutaneously with 5×l0 5 MS ＋ B16 cells.Compared with that of the negative control immunized with phosphate-buffered saline（PBS）,a significant reduction of tumor growth was observed in groups immunized with survivin plasmid DNA and MUC1 VNTRs plasmid DNA.Thus,the suppression of subcutaneous tumor was antigen-specific.This model is useful for the development of tumor vaccines targeting survivin and MUCI VNTRs.

HCA520, A NOVEL TUMOR ASSOCIATED ANTIGEN, INVOLVED IN CELL PROLIFERATION AND APOPTOSIS

Objective: Tumor associated antigen encoding gene HCA520 (AF146019) was identified by screening a human hepatocellular carcinoma expressing cDNA library using SEREX technique. In this experiment we studied the effect of HCA520 on cell proliferation and apoptosis. Methods: Gene HCA520 was gained by PCR and transfected into 293 cells. The stable expression cells were obtained by G418 selection. The cell proliferation was measured by [3H]-TdR uptake and apoptosis assay was measured by FACS. Results: Eukaryotic expression plasmid pcDNA3-HCA520 was constructed and its stable transfectants were obtained. Overexpression of HCA520 inhibited the cell proliferation and enhanced cell apoptosis after serum deprivation. Conclusion: HCA520 is a novel tumor associated antigen that can affect cell proliferation and apoptosis.

Tumor antigen and MHC expression in glioma cells for immunotherapeutic interventions

AIM: To investigate the expression of tumor-antigens and major histocompatibility complex(MHC)-machinery components in glioblastoma multiforme cell lines flow cytometry staining methods were applied.METHODS: Ten GBM cell lines(three commercially available: U-87 MG, U-138-MG and GMS-10 as well as seven newly established cell lines from individual patients in low-passages: HROG02, HROG04, HROG05, HROG06, HROG10, HROG13 and HROG17) were analyzed for expression of(Ⅰ) general and(Ⅱ) GBMrelated tumor antigens as well as of(Ⅲ) components of the MHC machinery by flow cytometry.RESULTS: All cell lines expressed MHC class?Ⅰ?with seven out of the ten being HLA-A02 positive. Four of the seven primary cell lines additionally expressedMHC class Ⅱ in a constitutive manner. Of note, after interferon gamma(IFN-γ) treatment, all seven cell lines expressed MHC class Ⅱ. The tumor associated antigens(TAA) EGFR and survivin were expressed at high levels in all cell lines; whereas MART-1, RHAMM, WT-1 and IL-13Rα were expressed by at least half of the cell lines and HER2/neu, MAGE-1 and tyrosinase were expressed only by few cell lines. However, all cell lines expressed at least two of the candidate antigens included into this analysis.CONCLUSION: No obvious differences between commercially available and newly-established cell lines were observed. Thus, the latter in low-passages are interesting for(therapy-) screening and immunotherapeutic strategies.

Changes in tumor-antigen expression profile as human small-cell lung cancers progress

Objective： Our group has previously observed that in patients with small-cell lung cancers （SCLCs）, the expression of a tumor antigen, glioma big potassium （gBK） ion channel, is higher at the time of death than when the cancer is first treated by surgical resection. This study aimed to determine whether this dichotomy was common in other potential lung tumor antigens by examining the same patient samples using our more extensive profile analysis of tumor-antigen precursor protein （TAPP）. We then tested the hypothesis that therapeutic intervention may inadvertently cause this increased gBK production. Methods： SCLC samples （eight surgical resections and three autopsy samples） and three control lungs were examined by quantitative real-time polymerase chain reaction for 42 potential TAPPs that represent potential T-cell-mediated immunological targets. Results： Twenty-two TAPP mRNAs displayed the same profile as gBK, i.e., more mRNAs were expressed at autopsy than in their surgical counterparts. B-cyclin and mouse double minute 2, human homolog of PS3-binding protein were elevated in both autopsy and surgical specimens above the normal-lung controls. When HTB119 cells were incubated with doxorubicin, gBK was strongly induced, as confirmed by intracellular flow cytometry with a gBK-specific antibody. Conclusion： Our findings suggested that more immunological targets became available as the tumor responded to chemotherapy and proceeded toward its terminal stages.

Isolation and Characterization of Exosomes Derived from Tumor Cells Genetically Expressing Model Antigen

Tumor cell-derived exosomes have been proposed as non-cellular nanomeric vaccine which could induce potent anti- tumor immune response in mice. In order to develop the protocols to prepare tumor cell-derived exosomes for basic research and clinical trail, we isolated exosomes from ovalbumin (OVA)-expressing thymoma cells EG.7-OVA by various preparation methods. We demonstrate the non-sedimentation method is simple, rapid, efficient with higher yield and purity of exosomes. EG.7-OVA-derived exosomes are 40-100 nm in diameter sequestered by lipid bi-layer, and contain rich heat shock protein (HSP) and OVA. The result of the size distribution determination is consistent with the calculation by the visual microscopic inspection, with 90.4% particles at the range of 50-90 nm. Moreover, as a model antigen of the EG.7 cells, OVA concentra- tion in EG.7-derived exosomes can be regarded as a good quality control parameter. Therefore, we have established a platform to efficiently prepare exosomes for tumor immunotherapy.

An experimental study on the expression of SV40 large tumor antigen in human brain tumors

Objective: To study the role of SV40 early region gene coding product large tumor antigen(Tag) expression and the interaction between Tag and tumor suppressors p53 and pRb in human brain tumorigenesis. Methods: Tag was investigated by immunoprecipitation followed by silver staining and Western blot in 65 cases of human brain tumors and 8 cases of normal brain tissues. Tag-p53 and Tag-pRb complexes were screened by immunoprecipitation and Western blot in 18 and 15 Tag positive tumor tissues respectively. Results: SV40 Tag was expressed generally in human brain tumors, its positive rate was 66. 2% (43 /65). However, Eight normal brain tissues were all negative for Tag, there was significant difference between them(P < 0. 05). Tag-p53 complex was detected in all of 18 Tag positive tumors as well as Tag-pRb complex in all of 15 Tag positive tumors. Conclnsion: SV40 Tag expression is associated with human brain tumorigenesis. The inactivation of p53 and pRh due to the formation of Tag-p53 and Tag-pRb complexes is possibly an important mechanism in the etiopathogenesis of human brain tumors.

Palliative primary tumor resection provides survival beneits for the patients with metastatic colorectal cancer and low circulating levels of dehydrogenase and carcinoembryonic antigen

Background: It remains controversial whether palliative primary tumor resection(PPTR) can provide survival benefits to the patients with metastatic colorectal cancer(m CRC) who have unresectable metastases. The aim of this study was to evaluate whether PPTR could improve the survival of patients with m CRC.Methods: We conducted a retrospective study on consecutive m CRC patients with unresectable metastases who were diagnosed at Sun Yat?sen University Cancer Center in Guangzhou, Guangdong, China, between January 2005 and December 2012. Overall survival(OS) and progression?free survival(PFS) after first?line chemotherapy failure were compared between the PPTR and non?PPTR patient groups.Results: A total of 387 patients were identified, including 254 who underwent PPTR and 133 who did not. The median OS of the PPTR and non?PPTR groups was 20.8 and 14.8 months(P < 0.001), respectively. The median PFS after first?line chemotherapy was 7.3 and 4.8 months(P < 0.001) in the PPTR and non?PPTR groups, respectively. A larger proportion of patients in the PPTR group(219 of 254, 86.2%) showed local progression compared with that of patients in the non?PPTR group(95 of 133, 71.4%; P < 0.001). Only patients with normal lactate dehydrogenase(LDH) levels and with carcinoembryonic antigen(CEA) levels <70 ng/m L benefited from PPTR(median OS, 22.2 months for the PPTR group and 16.2 months for the non?PPTR group; P < 0.001).Conclusions: For m CRC patients with unresectable metastases, PPTR can improve OS and PFS after first?line chemo?therapy and decrease the incidence of new organ involvement. However, PPTR should be recommended only for patients with normal LDH levels and with CEA levels <70 ng/m L.

Tumor-Specific Histo-Blood Group Antigens: Apropos of Two Cases

Cancer cells with immunogenic properties having altered protein glycosylation, modified blood group substances have been widely studied. Due to the genetic instability occurring during carcinogenesis the glycosyltransferases may suffer from posttranslation sequence modification. The author describes 2 autopsy cases, where in the background of the unusual metastatic tumor presentation, incompatible blood group antigenic determinants have been demonstrated using blood group specific lectins and monoclonal antibodies (mAb). In the first case, reported here, a 10-year-old girl developed an acute myeloid leukemia and died in a septic endotoxin shock after successful cytostatic treatment of a juvenile signet ring cell cancer of her colon. At autopsy there were no signs of tumor except bilateral apple-sized mucinous ovarian (Krukenberg) metastases. While she had erythrocyte phenotype of blood group A, the signet ring adenocarcinoma cells expressed blood group B incompatible antigenic determinants with lectin/mAb. In the second case, the autopsy of a 78-year-old female resulted in no macroscopic tumor sign except a moderately enlarged, ham hard spleen. Light microscopy revealed adenocarcinomatous infiltration in the splenic sinusoids. The patient had blood group O, while the metastatic cells in the spleen reacted with Breast Carcinoma Antigen (BioGenex) and incompatible anti-B Banderiaeasimplicifolia agglutinin I and anti-B mAb. It proved to be a case of an occult, completely regressed breast cancer. Based on these observations the expression of tumor specific incompatible blood group antigens might occur from time to time, mostly in adenocarcinomas. Accordingly, blood group-based specific immuno-oncotherapy could be considered in some cancer cases.

Effects of heat shock protein-antigen peptide complexes (HACs) in melanoma B16 cell line on transplanted tumor development in mice

目的 :建立黑色素瘤 B16细胞热休克蛋白 -抗原肽复合物 (HACs)的制备方法并测其抑瘤效应。方法 :应用 Sephacryl S- 2 0 0凝胶过滤制备 HAC粗提物 ,应用 SDS- PAGE纯化 HACs,并测其抑瘤效应。结果 :应用 SDS- PAGE纯化的 HAC6 0、 HAC75和 HAC97不同程度地降低肿瘤发生率 ,延迟肿瘤发生时间和减慢肿瘤生长速度。结论 :6 0 0 0 0～ 970 0 0

Cancer/testis antigens： novel tools for discerning aggressive and non-aggressive prostate cancer

The introduction of serum prostate-specific antigen （PSA） in the 1980s has dramatically altered and benefited the initial diagnosis of prostate cancer. However, the widespread use of PSA testing has resulted in overdetection and overtreatment of potentially indolent disease. Thus, a clinical dilemma today in the management of prostate cancer is to discern men with aggressive disease who need definitive treatment from men whose disease are not lethal. Although several serum and tissue biomarkers have been evaluated during the past decade, improved markers are still needed to enhance the accuracy, with which patients at risk can be discerned and treated more aggressively. The cancer/testis antigens （CTAs） are a group of proteins that are restricted to the testis in the normal adult, but are aberrantly expressed in several types of cancers. Because of their restricted expression pattern, the CTAs represent attractive biomarker candidates for cancer diagnosis/prognosis. Furthermore, several studies to date have reported the differential expression of CTAs in prostate cancer. Here, we review recent developments that demonstrate the potential of the CTAs as biomarkers to discern the a^ressive Dhenotvoe of orostate cancer.

Cancer/testis antigen, Kita-Kyushu lung cancer antigen-1 and ABCD stratification for diagnosing gastric cancers

BACKGROUND The ABCD stratification[combination of serum pepsinogen(PG)levels and titers of antibody(immunoglobulin G,IgG)against Helicobacter pylori(H.pylori)]is effective for the classification of individuals at risk of developing gastric cancer(GC).The Kita–Kyushu lung cancer antigen-1(KK-LC-1)is a Cancer/Testis antigen frequently expressed in GC.AIM To evaluate the effectiveness of KK-LC-1 and ABCD stratification in the diagnosis of GC.METHODS We analyzed the gene expression of KK-LC-1 in surgical specimens obtained from GC tumors.The levels of serum PG I/PG II and IgG against H.pylori were measured.According to their serological status,the patients were classified into the four groups of the ABCD stratification.RESULTS Of the 77 examined patients,63(81.8%)expressed KK-LC-1.The IgG titers of H.pylori and PG II were significantly higher in patients expressing KK-LC-1 than those measured in patients not expressing KK-LC-1(P=0.0289 and P=0.0041,respectively).The expression of KK-LC-1 in group C[PG method(+)/H.pylori infection(+)]was as high as 93.9%high.KK-LC-1 was also detected in group A[-/-].CONCLUSION The KK-LC-1 expression in GC was associated with H.pylori infection and atrophic status,so that,KK-LC-1 may be a useful marker for the diagnosis of GC.

Diagnostic value of elevated serum carbohydrate antigen 199 level in acute cholangitis secondary to choledocholithiasis

AIM To investigate the diagnostic value of abnormal serum carbohydrate antigen 199(CA199) level in acute cholangitis secondary to choledocholithiasis.METHODS In this retrospective cohort study, the clinical data of 727 patients with choledocholithiasis admitted to the Third Affiliated Hospital of Zunyi Medical College from June 2011 to June 2017 were collected. Among these patients, 258 patients had secondary acute cholangitis and served as observation group, and the remaining 569 choledocholithiasis patients served as the control group. Serum liver function indexes and tumor markers were detected in both groups, and the receiver operating characteristic(ROC) curves were constructed for markers showing statistical significances. The cutoff value, sensitivity, and specificity of each marker were calculated according to the ROC curves. RESULTS The results of liver function tests showed no significant differences between the two groups(P > 0.05). Tumor markers including serum CA125, CA153, carcinoembryonic antigen, and alpha fetoprotein levels were also not significantly different(P > 0.05); however, the serum CA199 level was significantly higher in the observation group than in the control group(P < 0.05). The ROC curve analysis showed that the area under the curve was 0.885(95%CI: 0.841-0.929) for CA199, and the cutoff value of 52.5 kU/L had the highest diagnostic accuracy, with a sensitivity of 86.8% and a specificity of 81.6%.CONCLUSION Abnormally elevated serum CA199 level has an important value in the diagnosis of acute cholangitis secondary to choledocholithiasis. It may be a specific inflammatory marker for acute cholangitis.

Selection of DNA aptamer that specific binding human carcinoembryonic antigen in vitro

Objective：To select the specific aptamer of carcinoembryonic antigen （CEA）, one of the most attractive molecule for cancer target therapy and imaging. Methods： Seven rounds in vitro selection were performed against the purified CEA protein. Ligand-mediated target purification and Co-immunoprecipitation were adopted to verify the specific binding of the aptamer to the purified and native protein separately. Results：The CEA-specific aptamer which can bind both the purified and native protein with the high specificity was obtained. Conclusion：This is the first time the CEA specific apatmer was produced. The results in this study provides the preliminary evidence for further investigation and application of CEA-aptamer in the future.

Chimeric antigen receptor-engineered T-cell therapy for liver cancer

Background: Chimeric antigen receptor-engineered T-cell(CAR-T) therapy is a newly developed immunotherapy used in the treatment of cancers. Because CAR-T therapy has shown great success in treating CD19-positive hematological malignancies, its application has been explored in the treatment of solid tumors, such as liver cancer. In this review, we discuss the immune characteristics of liver cancer, the obstacles encountered during the application of CAR-T therapy, and preclinical and clinical progress in the use of CAR-T therapy in patients with liver cancer.Data sources: The data on CAR-T therapy related to liver cancers were collected by searching Pub Med and the Web of Science databases prior to December 2017 with the keywords "chimeric antigen receptor","CAR-T", "liver cancer", "hepatocellular carcinoma", and "solid tumor". Additional articles were identified by manual search of references found in the primary articles. The data for clinical trials were collected by searching Clinical Trials.gov.Results: The liver has a tolerogenic nature in the intrahepatic milieu and its tumor microenvironment significantly affects tumor progression. The obstacles that reduce the efficacy of CAR-T therapy in solid tumors include a lack of specific tumor antigens, limited trafficking and penetration of CAR-T cells to tumor sites, and an immunosuppressive tumor microenvironment. To overcome these obstacles, several strategies have emerged. In addition, several strategies have been developed to manage the side effects of CAR-T, including enhancing the selectivity of CARs and controlling CAR-T activity. To date, no clinical trials of CAR-T therapy against HCC have been completed. However, preclinical studies in vitro and in vivo have shown potent antitumor efficacy. Glypican-3, mucin-1, epithelial cell adhesion molecule, carcinoembryonic antigen, and other targets are currently being studied.Conclusions: The application of CAR-T therapy for liver cancer is just beginning to be explored and more research is needed. However, we are optimistic that CAR-T therapy will offer a new approach for the treatment of liver cancers in the future.