Immunotherapy in leukaemia.

Leukaemia is the common name for a group of malignant diseases of the haematopoietic system with complex classifications and characteristics. Remarkable progress has been made in basic research and preclinical studies for acute leukaemia compared to that of the many other types/subtypes of leukaemia, especially the exploration of the biological basis and application of immunotherapy in acute myeloid leukaemia (AML) and B-cell acute lymphoblastic leukaemia (B-ALL). In this review, we summarize the basic approaches to immunotherapy for leukaemia and focus on the research progress made in immunotherapy development for AML and ALL. Importantly, despite the advances made to date, big challenges still exist in the effectiveness of leukaemia immunotherapy, especially in AML. Therefore, we use AML as an example and summarize the mechanisms of tumour cell immune evasion, describe recently reported data and known therapeutic targets, and discuss the obstacles in finding suitable treatment targets and the results obtained in recent clinical trials for several types of single and combination immunotherapies, such as bispecific antibodies, cell therapies (CAR-T-cell treatment), and checkpoint blockade. Finally, we summarize novel immunotherapy strategies for treating lymphocytic leukaemia and clinical trial results.

Radiomic and clinical data integration using machine learning predict the efficacy of anti-PD-1 antibodies-based combinational treatment in advanced breast cancer: a multicentered study.

BACKGROUND: Immune checkpoint inhibitors (ICIs)-based therapy, is regarded as one of the major breakthroughs in cancer treatment. However, it is challenging to accurately identify patients who may benefit from ICIs. Current biomarkers for predicting the efficacy of ICIs require pathological slides, and their accuracy is limited. Here we aim to develop a radiomics model that could accurately predict response of ICIs for patients with advanced breast cancer (ABC). METHODS: Pretreatment contrast-enhanced CT (CECT) image and clinicopathological features of 240 patients with ABC who underwent ICIs-based treatment in three academic hospitals from February 2018 to January 2022 were assigned into a training cohort and an independent validation cohort. For radiomic features extraction, CECT images of patients 1 month prior to ICIs-based therapies were first delineated with regions of interest. Data dimension reduction, feature selection and radiomics model construction were carried out with multilayer perceptron. Combined the radiomics signatures with independent clinicopathological characteristics, the model was integrated by multivariable logistic regression analysis. RESULTS: Among the 240 patients, 171 from Sun Yat-sen Memorial Hospital and Sun Yat-sen University Cancer Center were evaluated as a training cohort, while other 69 from Sun Yat-sen University Cancer Center and the First Affiliated Hospital of Sun Yat-sen University were the validation cohort. The area under the curve (AUC) of radiomics model was 0.994 (95% CI: 0.988 to 1.000) in the training and 0.920 (95% CI: 0.824 to 1.000) in the validation set, respectively, which were significantly better than the performance of clinical model (0.672 for training and 0.634 for validation set). The integrated clinical-radiomics model showed increased but not statistical different predictive ability in both the training (AUC=0.997, 95% CI: 0.993 to 1.000) and validation set (AUC=0.961, 95% CI: 0.885 to 1.000) compared with the radiomics model. Furthermore, the radiomics model could divide patients under ICIs-therapies into high-risk and low-risk group with significantly different progression-free survival both in training (HR=2.705, 95% CI: 1.888 to 3.876, p<0.001) and validation set (HR=2.625, 95% CI: 1.506 to 4.574, p=0.001), respectively. Subgroup analyses showed that the radiomics model was not influenced by programmed death-ligand 1 status, tumor metastatic burden or molecular subtype. CONCLUSIONS: This radiomics model provided an innovative and accurate way that could stratify patients with ABC who may benefit more from ICIs-based therapies.

Hepato-specific microRNA-122 facilitates accumulation of newly synthesized miRNA through regulating PRKRA.

microRNAs (miRNAs) are a versatile class of non-coding RNAs involved in regulation of various biological processes. miRNA-122 (miR-122) is specifically and abundantly expressed in human liver. In this study, we employed 3'-end biotinylated synthetic miR-122 to identify its targets based on affinity purification. Quantitative RT-PCR analysis of the affinity purified RNAs demonstrated a specific enrichment of several known miR-122 targets such as CAT-1 (also called SLC7A1), ADAM17 and BCL-w. Using microarray analysis of affinity purified RNAs, we also discovered many candidate target genes of miR-122. Among these candidates, we confirmed that protein kinase, interferon-inducible double-stranded RNA-dependent activator (PRKRA), a Dicer-interacting protein, is a direct target gene of miR-122. miRNA quantitative-RT-PCR results indicated that miR-122 and small interfering RNA against PRKRA may facilitate the accumulation of newly synthesized miRNAs but did not detectably affect endogenous miRNAs levels. Our findings will lead to further understanding of multiple functions of this hepato-specific miRNA. We conclude that miR-122 could repress PRKRA expression and facilitate accumulation of newly synthesized miRNAs.

Promyelocytic leukemia protein interacts with werner syndrome helicase and regulates double-strand break repair in γ-irradiation-induced DNA damage responses.

We show here that γ-irradiation leads to the translocation of endogenous Werner syndrome helicase (WRN) from nucleoli to nucleoplasmic DNA double strand breaks (DSBs), and WRN plays a role in damage repair. The relocation of WRN after irradiation was perturbed by promyelocytic leukemia protein (PML) knockdown and enhanced by PML IV overexpression. PML IV physically interacted with WRN after irradiation. Amino acids (a.a.) 394 to 433 of PML were necessary for this interaction and the nucleoplasmic translocation of WRN and were involved in DSB repair and cellular sensitivity to γ-irradiation. Taken together, our results provide molecular support for a model in which PML IV physically interacts with and regulates the translocation of WRN for DNA damage repair through its 394-433 a.a. domain.

p53 Suppresses lung resistance-related protein expression through Y-box binding protein 1 in the MCF-7 breast tumor cell line.

Lung resistance-related protein (LRP) has roles in multi-drug resistance of tumor cells. Understanding the mechanisms that regulate LRP expression in tumor cells is an important research area. A putative p53 response element in the LRP promoter has been found. Thus, p53-related regulation of LRP expression was explored in this study. We first demonstrated that p53 overexpression inhibited LRP expression both at the protein and mRNA levels. Then, using a dual-luciferase reporter assay, we located the p53 response element to the Y-box (-263~-407) of the LRP promoter, the YB-1 binding site, but not the putative p53 response element. Furthermore, coimmunoprecipitation and chromatin immunoprecipitation showed p53 could bind to the Y-box of the LRP promoter through interaction of p53 with YB-1. YB-1 coexpression with p53 facilitated p53-induced suppression of endogenous LRP expression in MCF-7 cells. HDAC2, a corepressor of p53, was found to also interact with YB-1, and this interaction was mediated by p53. These results showed that the p53-HDAC2 transcriptional repressor complex can bind to the Y-box of the LRP promoter and repress LRP expression through interaction with YB-1. p53-related suppression of LRP expression was completely reversed by doxorubicin treatment and Adr, whereas CP and VP-16 treatment induced LRP expression increased significantly. Inhibition of LRP expression by siRNA facilitated Adr induced apoptosis of MCF-7 cells. All these findings indicated that loss of p53-related suppression of LRP may be the reason for LRP expression increase, and, therefore, chemotherapy resistance in tumor cells.

Functional proteomic analysis of promyelocytic leukaemia nuclear bodies in irradiation-induced MCF-7 cells.

It is well established that promyelocytic leukaemia nuclear bodies (PML NBs) play important roles in DNA damage responses (DDR). After irradiation, PML NBs dynamically recruit or release important proteins involved in cell-cycle regulation, DNA repair and apoptosis. As PML protein is the key molecule of PML NBs' dynamic assembling, we aimed to characterize the PML-interacting proteins in (60)Co-irradiated MCF-7 cells. A proteomic approach using CoIP, mono-dimensional electrophoresis and tandem mass spectrometry, allowed us to identify a total of 124 proteins that may associate with PML after irradiation. Bioinformatic analysis of the identified proteins showed that most of them were related to characterized PML functions, such as transcriptional regulation, cell-cycle regulation, cell-death regulation and response to stress. Four proteins, B23, MVP, G3BP1 and DHX9, were verified to co-localize with PML differentially before and after ionizing radiation (IR) treatment. The proteins identified in this study will significantly improve our understanding of the dynamic organization and multiple functions of PML NBs in DDR.

MicroRNA-193b regulates proliferation, migration and invasion in human hepatocellular carcinoma cells.

BACKGROUND AND AIMS: Recently, some miRNAs have been reported to be connected closely with the development of human hepatocellular carcinoma. However, the functions of these miRNAs in HCC remain largely undefined. METHODS: The expression profiles of miR-193b were compared between HCC tissues and adjacent normal liver tissues using qRT-PCR method. This method was also be used to screen the potential target genes of miR-193b. A luciferase reporter assay was conducted to confirm target association. Finally, the functional effect of miR-193b in hepatoma cells was examined further. RESULTS: miR-193b was significantly down-regulated in most of the HCC tissues compared to the matching non-tumoural liver tissues. Furthermore, ectopic expression of miR-193b dramatically suppressed the ability of hepatoma cells to form colonies in vitro and to develop tumours in nude mice. CCND1 and ETS1 were revealed to be regulated by miR-193b directly. By regulating the expressions of these oncogenes, miR-193b induced cell cycle arrest and inhibited the invasion and migration of hepatoma cells. CONCLUSIONS: miR-193b may function as a tumour suppressor in the development of HCC by acting on multiple tumourigenic pathways.

miR-183 inhibits TGF-beta1-induced apoptosis by downregulation of PDCD4 expression in human hepatocellular carcinoma cells.

BACKGROUND: In recent years, some miRNAs have been reported to be connected closely with the development of human hepatocellular carcinoma. In our previous studies, a set of miRNAs were revealed to be dysregulated in HCC tissues. However, the functions of these miRNAs in HCC remain largely undefined. METHODS: The expression profiles of miR-183 were compared between HCC tissues and adjacent normal liver tissues using qRT-PCR method. This method was used to screen the potential target genes of miR-183. A luciferase reporter assay was conducted to confirm target association. Finally, the functional effect of miR-183 in hepatoma cells was examined. RESULTS: Among the 25 HCC samples analyzed, microRNA-183 was significantly up-regulated (twofold to 367-fold) in 17 samples compared with the matching nontumoral liver tissues. Programmed cell death 4 (PDCD4) was identified as the target gene of miR-183. Moreover, PDCD4 is a proapoptotic molecule involved in TGF-beta1-induced apoptosis in human HCC cells, we found that miR-183 transfectants were resistant to apoptosis induced by TGF-beta1. CONCLUSIONS: We conclude that miR-183 can inhibit apoptosis in human HCC cells by repressing the PDCD4 expression, and miR-183 may play an important role in HCC development.

MicroRNA-101 regulates expression of the v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) oncogene in human hepatocellular carcinoma.

UNLABELLED: MicroRNAs (miRNAs) have recently been proposed as a versatile class of molecules involved in regulation of various biological processes. Although there is emerging evidence that some microRNAs can function as oncogenes or tumor suppressors, the specific role of miRNA in human hepatocellular carcinoma (HCC) is unclear at this point. In this study, we examined the microRNA expression profiles in a set of 20 human HCC specimens by miRNA microarray and quantitative real-time polymerase chain reaction. The results showed that among the 20 HCC samples analyzed, microRNA-101 was significantly down-regulated twofold or more (twofold to 20-fold) in 16 samples compared with the matching nontumoral liver tissues. Using both a luciferase reporter assay and Western blot analysis, we showed that microRNA-101 repressed the expression of v-fos FBJ murine osteosarcoma viral oncogene homolog (FOS) oncogene, a key component of the activator protein-1 (AP-1) transcription factor. Moreover, using a luciferase expression vector (pAP-1-Luc) driven by seven copies of an AP-1 cis-element, we observed that microRNA-101 expression inhibited phorbol 12-myristate 13-acetate (PMA)-induced AP-1 activity. In in vitro Matrigel invasion and Transwell migration assays, enhanced microRNA-101 expression inhibited the invasion and migration of cultured HCC cells, respectively. These findings suggest that microRNA-101 may play an important role in HCC. CONCLUSION: MicroRNA-101, which is aberrantly expressed in HCC, could repress the expression of the FOS oncogene.

miR-16 family induces cell cycle arrest by regulating multiple cell cycle genes.

MicroRNAs (miRNAs) are a class of small regulatory RNAs that are thought to be involved in diverse biological processes by regulating gene expression. Numerous miRNAs have been identified in various species, and many more miRNAs remain to be detected. Generally, hundreds of mRNAs have been predicted to be potential targets of one miRNA, so it is a great challenge to identify the genuine miRNA targets. Here, we generated the cell lines depleted of Drosha protein and screened dozens of transcripts (including Cyclin D1) regulated potentially by miRNA-mediated RNA silencing pathway. On the basis of miRNA expressing library, we established a miRNA targets reverse screening method by using luciferase reporter assay. By this method, we found that the expression of Cyclin D1 (CCND1) was regulated by miR-16 family directly, and miR-16 induced G1 arrest in A549 cells partially by CCND1. Furthermore, several other cell cycle genes were revealed to be regulated by miR-16 family, including Cyclin D3 (CCND3), Cyclin E1 (CCNE1) and CDK6. Taken together, our data suggests that miR-16 family triggers an accumulation of cells in G0/G1 by silencing multiple cell cycle genes simultaneously, rather than the individual target.

Differential sensitivity of colorectal cancer cell lines to artesunate is associated with expression of beta-catenin and E-cadherin.

Artesunate, a remarkable antimalarial agent, also reveals profound cytotoxic activity. In the present investigation, we compared the anticancer effects of artesunate on three colorectal cancer cell lines and analyzed the relationship between drug sensitivity and malignant phenotype of the tumor cells. The findings are as follows: poorly-differentiated was colorectal cancer cell line CLY showing nuclear beta-catenin accumulation and loss of E-cadherin; moderately-differentiated were Lovo cells with cytoplasmic distribution of the two proteins; and well-differentiated were HT-29 cells with membranous localization of them. Also, both in vitro and in vivo, poorly- or moderately-differentiated CLY and Lovo were more susceptible to artesunate treatment than well-differentiated HT-29. Furthermore, the sensitive response of CLY and Lovo to artesunate was associated with membranous translocation of beta-catenin and increased expression of E-cadherin, which indicated the inhibition of hyperactive Wnt signaling pathway and the reversion of the epithelial to mesenchymal transition, respectively. Due to the vital roles of Wnt pathway and the epithelial to mesenchymal transition in tumor differentiation, we thought artesunate could promote the re-differentiation and apoptosis of colorectal cancer cells by inhibition of hyperactive Wnt pathway and reversion of the epithelial to mesenchymal transition.

Survivin knockdown combined with apoptin overexpression inhibits cell growth significantly.

The initiation and progression of tumor is regulated by multiple genes. Survivin belongs to the inhibitor of apoptosis protein (IAP) family and is overexpressed in most types of human tumors. Apoptin, originally identified from chicken anemia virus (CAV), can specifically induce apoptosis of human tumor cells rather than normal cells. In this study, survivin expression was silenced by microRNA (miRNA)-mediated RNA interference (RNAi); meanwhile, the engineered miRNA vector was also designed to express apoptin gene. The apoptosis and cell growth were then examined by flow cytometry and MTT assay. The miRNA-mediated knockdown of survivin in combination with apoptin overexpression significantly induced apoptosis and inhibited cell growth. Importantly, the combined strategy was more effective on inducing apoptosis and inhibiting cell growth than either survivin downregulation or apoptin overexpression alone. Taken together, the combined strategy offers potential advantages in control of tumorigenesis, and thus deserves further research as a preferred approach in cancer gene therapy.

Downregulation of CCND1 and CDK6 by miR-34a induces cell cycle arrest.

miRNAs regulate gene expression by inhibiting translation or by targeting messenger RNA (mRNA) for degradation in a post-transcriptional fashion. In the present study, we show that ectopic expression of miR-34a reduces both mRNA and protein levels of cyclin D1 (CCND1) and cyclin-dependent kinase 6 (CDK6). We also demonstrate that miR-34a targets the 3'-untranslated mRNA region of CCND1 as well as CDK6, which in turn interferes with phosphorylation of retinoblastoma. In addition, we show that overexpression of miR-34a induces a significant G1 cell-cycle arrest in the A549 cell line. Taken together, our data suggest that the effects of miR-34a on G1 cell cycle arrest are through the down-regulation of CCND1 and CDK6, which is associated with other targets of miR-34a either additively or synergistically.

Artesunate attenuates the growth of human colorectal carcinoma and inhibits hyperactive Wnt/beta-catenin pathway.

Artesunate (ART), a remarkable antimalarial agent, also inhibited the growth of human colorectal carcinoma. As determined by MTT assay, flow cytometry analysis on apoptosis and indirect immunofluorescence analysis on the proliferation-associated marker Ki67, ART suppressed the proliferation and promoted the apoptosis of colorectal cancer cells in a dose-dependent manner. Furthermore, immunofluorescence analysis on beta-catenin and RT-PCR analysis on Wnt/beta-catenin target genes demonstrated ART translocated beta-catenin from nucleus to adherent junctions of membrane and reduced transcription mediated by beta-catenin. These results suggested the anticancer activity of ART correlated with the inhibition of hyperactive Wnt/beta-catenin signaling pathway. In vivo, ART significantly slowed the growth of colorectal tumor xenografts. Bioluminescent imaging also revealed that ART decreased the physiological activity of tumor xenografts and delayed spontaneous liver metastasis. These antitumor effects were related to the membranous translocation of beta-catenin and the inhibition of the unrestricted activation of Wnt/beta-catenin pathway, which was confirmed by the immunohistochemical staining of tumor tissues. These results and the known low toxicity are clues that ART might be a promising candidate drug for the treatment of colorectal carcinoma.

The PH domain containing protein CKIP-1 binds to IFP35 and Nmi and is involved in cytokine signaling.

The pleckstrin homology domain-containing protein CKIP-1 is implicated in regulation of cell differentiation, apoptosis, cytoskeleton as well as recruitment of CK2 and ATM kinases to plasma membrane. Protein-protein interactions of CKIP-1 were required for these functions. Here we identify the IFN-induced protein IFP35 and its homologue Nmi as two novel CKIP-1 interacting partners. The NID domains of IFP35 and Nmi are required for the interactions. Similar to IFP35 and Nmi, CKIP-1 can be up-regulated dramatically by IFN-gamma and IL-2 and form homodimer and homotrimer in vivo. Nmi stabilizes IFP35, whereas CKIP-1 destabilizes IFP35 via inhibiting IFP35-Nmi interaction. The ratio of Nmi to CKIP-1 determines the stability of IFP35 and control cytokine signaling in a novel mechanism. Importantly, similar to Nmi and contrast to IFP35, CKIP-1 inhibits tumor cell growth and Akt-mediated cell survival. Thus, our results provide a novel role of CKIP-1 in cytokine signaling response and the biochemical mechanism, by which two previously identified modulators IFP35 and Nmi are involved via interactions.

[Proteomic analysis of G2/M arrest of HL-60 cells induced by MG132].

BACKGROUND & OBJECTIVE: Proteasome inhibitor, which can induce apoptosis in various tumor cells, is a kind of potential antitumor drug. This study was to identify the proteins involved in G(2)/M arrest of leukemia cell line HL-60 exposed to proteasome inhibitor MG132 by proteomic techniques. METHODS: Flow cytometry was used to examine cell cycle of HL-60 cells exposed to 2.5 micromol/L MG132. Nuclear extracts of HL-60 cells were prepared, and the purity was detected by light microscopy and Western blot, and the differentially expressed protein spots were determined by two-dimensional gel electrophoresis and identified with MALDI-TOF-TOF/MS. RESULTS: There was a distinct G(2)/M phase arrest before the apoptosis of HL-60 cells induced by 2.5 micromol/L MG132. Twenty-three differentially expressed protein spots were found between MG132-treated and control HL-60 cells; 8 nuclear proteins were identified by MALDI-TOF-TOF/MS analysis. CONCLUSIONS: The detected proteins, such as eIF5A and splicing factor, may be involved in regulation of G(2)/M arrest of HL-60 cells. These findings will be helpful for revealing molecular mechanisms of proteasome inhibitor-induced G(2)/M phase arrest and apoptosis of leukemia cell line.

A novel method to monitor the expression of microRNAs.

The microRNAs (miRNAs) are an extensive class of small noncoding RNAs (18-25 nucleotides) with important roles in the regulation of gene expression. Although a large number of miRNAs have been identified in a variety of eukaryotic systems, the function of the vast majority of these molecules remains unknown. To study the functions of miRNAs, it is crucial to determine their spatial and temporal expression patterns. Although there are some existing methods that can analyze the expression of miRNAs, it is not an easy task for routine gene-expression studies. In this study, we have established a simple method to detect the expression of mature miRNAs. Total RNA was polyadenylated by poly(A) polymerase, and then cDNA was synthesized by a specific reverse transcriptase (RT) primer and reverse transcriptase using the poly(A)-tailed total RNA as templates. The expression of several mature miRNAs was assayed by this method. The expression profile of two miRNAs, determined by the polymerase chain reaction (PCR) assay, was identical to that determined by Northern blotting. All these data show that the poly(A)-tailed RT-PCR is a convenient method to detect the expression of miRNAs.

CKIP-1 recruits nuclear ATM partially to the plasma membrane through interaction with ATM.

CKIP-1 (casein kinase-2 interacting protein-1) is implicated in muscle differentiation, regulation of cell morphology and actin cytoskeleton. More recently, we showed that CKIP-1 regulated AP-1 activity and promoted apoptosis via caspase-3-dependent cleavage and translocation. Here, we report that overexpression of CKIP-1 in SK-BR-3 breast cancer cells prevents p53 degradation induced by cycloheximide treatment through increase of p53 N-terminal Ser-15 phosphorylation level. CKIP-1 could interact with ATM, which is an upstream kinase of p53, thereby enhance the stability of p53. Interestingly, CKIP-1 is localized both at the plasma membrane and in the nucleus dependent on the cell types, and only the plasma membrane-localized CKIP-1 could form a complex with ATM. Importantly, CKIP-1 recruits nuclear ATM proteins partially to the plasma membrane. Our data provide the first evidence that ATM, a predominantly nuclear kinase, could be relocalized to the plasma membrane by CKIP-1 and shed new light on the multi-functional CKIP-1.

[Inhibiting expression of human telomerase reverse transcriptase promotes degradation of survivin protein].

BACKGROUND & OBJECTIVE: The expression of Survivin in cancer cells highly correlates with that of human telomerase reverse transcriptase (hTERT). Both of them are ideal targets for cancer gene therapy. This study aimed to clarify if they regulate each other in cancer cells. METHODS: The expressions of Survivin and hTERT in HeLa S3 cells were inhibited by antisense oligonucleotide respectively. Activity of telomerase was detected by telomerase repeat amplification (TRAP) assay. Protein and mRNA levels of Survivin were analyzed by Western blot and reverse transcription-polymerase chain reaction (RT-PCR) respectively. Proliferation of HeLa S3 cells was analyzed by MTT assay. RESULTS: Inhibiting the expression of Survivin in HeLa S3 cells had no effects on telomerase activity. Inhibiting the expression of hTERT by antisense oligonucleotide No.14 decreased protein level of Survivin, which was negatively correlated with the concentration of No.14 (200-1 000 nmol/L), but didn't change mRNA level of survivin. The decrease of Survivin level was inhibited by proteasome inhibitor lactacystin and MG132. Furthermore, simultaneous inhibition of hTERT and survivin co-efficiently inhibited proliferation of HeLa S3 cells. CONCLUSION: Inhibiting the expression of hTERT in HeLa S3 cells promotes ubiquitin-proteasome degradation of Survivin.

[The epitope analysis of beta Netrin and preparation and characterization of its antibodies].

AIM: To prepare and characterize anti-human beta-Netrin antibodies. METHODS: B cell dominant epitopes of human beta-Netrin C-terminal 114 amino acid sequences were predicated by the GoldKey software. One of the epitopes was synthesized and coupled with bovine serum album (BSA) by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC). The BALB/c mice were immunized with the coupled protein. The splenocytes of immunized mice were fused with Sp2/0 cells by routine method and the hybridomas were selected in HAT medium. The hybridoma cells secreting specific antibody were detected by ELISA and cloned by limiting dilution. The titer specificity, and Ig subclass of anti-beta-Netrin mAbs were characterized by ELISA, Western blot and immunocytochemical staining. In addition, New Zealand rabbits were immunized with the coupled protein to prepare polyclonal antibody against beta-Netrin. The specificity of the antiserum was verified by Western blot. RESULTS: A 16-mer peptide NH2-FRGKRTLYPES-WTDRG-COOH was the dominant epitope of the B cells. Synthesized peptide coupled with BSA was used as the immunogen to immunize BALB/c mice. Three hybridoma cell lines that stably secrete specific mAbs were obtained. The result of immunocytochemical staining showed that prepared mAb specifically recognize the antigen in the neuronal cells. The polyclonal antibody against beta-Netrin had high specificity. Western blot analysis showed that the antiserum bind with the prokaryotically expressed beta-Netrin specifically. CONCLUSION: Using the synthesized peptides as hapten, we have prepared epitope-specific mAbs and pAb against beta-Netrin successfully.