Wilm′s tumor gene1肽疫苗Galinpepimut-S在肿瘤免疫治疗中的应用

目的为Wilm′s tumor gene1(WT1)肽疫苗Galinpepimut-S(GPS)用于肿瘤免疫治疗的后续研究提供参考。方法采用计算机检索中国知网、PubMed等数据库自建库起至2022年12月的肿瘤免疫治疗相关文献,总结GPS在肿瘤免疫治疗中的应用现状。结果GPS能激发自身免疫系统,对WT1抗原产生强烈免疫反应而发挥抗肿瘤作用,在卵巢癌、恶性胸膜间皮瘤、急性髓系白血病、多发性骨髓瘤的治疗中均显示出较好的疗效。结论以GPS为代表的肿瘤疫苗是未来肿瘤治疗的重要方向,需进一步进行临床研究,以获取更多数据。

The role of tazarotene-induced gene 1 in carcinogenesis:is it a tumor suppressor gene or an oncogene?

Tazarotene-induced gene 1(TIG1)is induced by a derivative of vitamin A and is known to regulate many important biological processes and control the development of cancer.TIG1 is widely expressed in various tissues;yet in many cancer tissues,it is not expressed because of the methylation of its promoter.Additionally,the expression of TIG1 in cancer cells inhibits their growth and invasion,suggesting that TIG1 acts as a tumor suppressor gene.However,in some cancers,poor prognosis is associated with TIG1 expression,indicating its protumor growth characteristics,especially in promoting the invasion of inflammatory breast cancer cells.This review comprehensively summarizes the roles of the TIG1 gene in cancer development and details the mechanisms through which TIG1 regulates cancer development,with the aim of understanding its various roles in cancer development.

Cloning and Expression Analysis of a Human Putative Tumor Suppressor Gene Homologue from Rice

A gene homologous to the human Putative tumor suppressor gone QM, designated OSQM1, was isolated from rice (Oryza sativa L.) genomic DNA library using through homology screening. It contained 4 exons and 3 introns, encoding a protein of 219 amino acids with 46 basic amino acids, leading to a high isoelectric point of 11.02. Homology search showed that this gene existed in eukaryotes and highly conserved throughout eukaryotes, suggesting an essential role of this gene. Northern Not analysis showed that it was expressed in various rice organs, but at lower level in developing flower and callus tissue than in other vegetative organs. Its expression levels in roots and leaves were influenced by different environmental factors.

Overexpression and mutations of tumor suppressor gene p53 in hepatocellular carcinoma

AIMS To examine the prevalance of p53 mutations in hepatocellular carcinoma (HCC) from Chongqing area and the relationship between the p53 mutations and clinicopathological features of HCC,as well as the risk factors. METHODS The overexpression and point mutations of tumor suppressor gene p53 in 38 cases of HCC were detected by a sensitive antigen retrieval fluid (ARF) immunohistochemical method and polymerase chain re- action(PCR)-restriction fragment length polymorphism (RFLP),and single strand conformation polymorphism (SSCP)-silver staining analysis. RESULTS The results showed that 16 of 38 HCCs had positive p53 protein (42.1%),7 HCCs had p53 mutation at 249 (18.4 % ) and 2 HCCS had point muta- tion within exon 7 other than 249. Among 9 cases of HCC with mutations,8 cases demonstrated positive p53 protein,its coincidental rate was 88.9%. The overexpression and mutations of p53 were significantly related to the differentiation and metastasis of HCCs. The frequency of p53 mutations was consistent with high prevalence of HBV and a moderate aflatoxin B1 (AFB1) exposure in our area. CONCLUSIONS The results suggest that AFB1 acts synergistically with HBV in the generation of p53 mutations. Furthermore,dietary exposure to AFB1 may mainly contribute to the tumor specific mutation at codon 249,while HBV may account for other scattered mutations in HCC.

Characterization of six tumorsuppressor genes and microsatellite instability in hepatocellular carcinomain southern African blacks

AIM To analyse cumulative loss of heterozygosity (LOH) of chromosomal regions and tumor suppressor genes in hepatocellular carcinomas (HCCs) from 20 southern African blacks. METHODS p53, RB1, BRCA1, BRCA2, WT1 and E cadherin genes were analysed for LOH, and p53 gene was also analysed for the codon 249 mutation, in tumor and adjacent non tumorous liver tissues using molecular techniques and 10 polymorphic microsatellite markers. RESULTS p53 codon 249 mutation was found in 25% of the subjects, as was expected, because many patients were from Mozambique, a country with high aflatoxin B 1 exposure. LOH was found at the RB1, BRCA2 and WT1 loci in 20%(4/*!20) of the HCCs, supporting a possible role of these genes in HCC. No LOH was evident in any of the remaining genes. Reports of mutations of p53 and RB1 genes in combination, described in other populations, were not confirmed in this study. Change in microsatellite repeat number was noted at 9/*!10 microsatellite loci in different HCCs, and changes at two or more loci were detected in 15%(3/*!20) of subjects. CONCLUSION We propose that microsatellite/genomic instability may play a role in the pathogenesis of a subset of HCCs in black Africans.

Potential roles of tumor suppressor genes and microsatellite instability in hepatocellular carcinogenesis in southern African blacks

MAJOR POINTS OF THE COMMENTED ARTICLECumulative loss of heterozygosity(LOH)ofchromosomal regions and tumor suppressor geneshas been reported in hepatocellular carcinomas(HCCs) from China,Japan,and Korea.In thisissue of the World Journal of Gastroenterology,Martins et al report an analysis of LOH andmicrosatellite instability in HCCs from a group of

Hypermethylation and expression regulation of secreted frizzled-related protein genes in colorectal tumor

AIM： To investigate the functions of promoter hypermethylation of secreted frizzled-related proteins （sFRPs） genes in colorectal tumorigenesis and progression. METHODS： The promoter hypermethylation and expression of sFRP genes in 72 sporadic colorectal carcinomas, 33 adenomas, 18 aberrant crypt foci （ACF） and colorectal cancer cell lines RKO, HCT116 and SW480 were detected by methylation-specific PCR and reverse transcription PCR, respectively. RESULTS： None of the normal colorectal mucosa tissues showed methylated bands of any of four sFRP genes, sFRP1, 2, 4 and 5 were frequently methylated in colorectal carcinoma, adenoma and ACF （sFRP1 〉 85%, sFRP2 〉75%, sFRP5 〉 50%）, and the differences between three colorectal tissues were not significant （P 〉 0.05）. IVlethylation in colorectal tumors was more frequent than in normal mucosa and adjacent normal mucosa. The mRNA of sFRP1-5 genes was expressed in all normal colorectal mucosa samples. Expression of sFRP1, 2, 4 and 5 and sFRP1, 2 and 5 was downregulated in carcinoma and adenoma, respectively. The downregulation of sFRP2, 4 and 5 was more frequent in carcinoma than in adenoma. Expression of sFRP3 which promoter has no CpG island was downregulated in only a few of colorectal tumor samples （7/105）. The downregulation ofsFRP1, 2, 4 and 5 expression was significantly associated with promoter hypermethylation in colorectal tumor. After cells were treated by DAC/TSA combination, the silenced sFRP mRNA expression could be effectively re-expressed in colorectal cancer cell lines. CONCLUSION： Hypermethylation of sFRP genes is a common early event in the evolution of colorectal tumor, occurring frequently in ACF, which is regarded as the earliest lesion of multistage colorectal carcinogenesis. It appears to functionally silence sFRP genes expression. Methylation of sFRP1, 2 and 5 genes might serve as indicators for colorectal tumor.

Effect of 5-Aza-2'-deoxycytidine on the P16 tumor suppressor gene in hepatocellular carcinoma cell line HepG2

INTRODUCTIONHepatocellular carcinoma (HCC) is one of the mostcommon human malignancies worldwide[1,2], and isclosely associated with infection of HBV and HCVand contamination of aflatoxin B1[3-6]. Althoughthe molecular mechanisms of hepatocarcinogenesisremain poorly understood, an increasing number ofgenetic abnormalities have been recognized[7-10],for example, the p16 gene[11,12] the p53gene[13-18], the E-cadherin gene[19], and the c-mycgene[20].

Inactivation of RASSF1A, the tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma

AIM: To evaluate the genetic and epigenetic inactivation mechanism of the RASSF1A tumor suppressor gene at 3p21.3 in extrahepatic cholangiocarcinoma. METHODS: RT-PCR was used to investigate the transcriptional expressing and re-expression of RASSFIA. RASSFIA mutation was analyzed with SSCP and selective sequencing. PCR was performed to detect the loss of heterozygosity (LOH) at the region of chromosome 3p21.3. Genomic DNA were modificated bisulfite and the frequency of methylation of CpG islands in RASSFIA promoter were evaluated by methylation specific PCR (MS-PCR). RESULTS: In all 48 samples and one cell lines of extrahepatic cholangiocarcinoma, the RASSFIA mutation is rare (6.12%, 3/49), 33 samples (68.75%) and QBC-939 cell lines (X2= 14.270, P= 0.001<0.01) showed RASSFIA express inactivation with LOH at microsatellite loci D3S4604. Among these 33 samples and QBC-939, 28 of 33 (84.85%) tumor samples and 1 cell lines were methylated for majority of 16 CpGs, the average frequency is 73.42%. CONCLUSION: The data we present suggest that RASSFIA which we have been searching for at 3p21.3 may be one of the key tumor suppressor gene and play an important role in the pathogenesis of extrahepatic cholangiocarcinoma, and the promoter methylation and allelic loss are the major mechanism for inactivation of RASSFIA.

Protein Expression of BLM Gene and Its Apoptosis Sensitivity in Hematopoietic Tumor Cell Strains

Patients with Bloom syndrome （BS） show an immunodeficiency, an enhanced sister chromatid exchanges （SCEs）, a strong genetic instability and an increased predisposition to all. In order to investigate the differential expression of BLM protein in hematopoietic tumor cell strains and study the effects of BLM gene on ultraviolet （UV）- or hydroxyurea （HU）-induced apoptosis, Western blot was used to detect the expression of BLM protein in normal human bone marrow mononuclear cells and 4 kinds of hematopoietic tumor cell strains. The 4 kinds of hematopoietic tumor cells were exposed to UV light with a germicidal UV lamp or treated with 2 mmol/L hydroxyurea and the apoptotic rate was detected by using AnnexinV-FITC. The results showed that these tumor cells expressed BLM protein higher than the normal human bone marrow mononuclear cells （P〈0.01）. In the 4 hematopoietic tumor cells, BLM protein was all specially cleaved in response to UV- or HU-induced apoptosis. The increase of BLM protein expression may play an important role in the development of these tumors, and BLM proteolysis is likely to be a general feature of the apoptotic response.

Alteration of tumor suppressor gene p16 and Rb in gastric cancinogesis

IM To study the alterations of tumor suppressor gene p16 and Rb in the carcinogenesis of the stomach. METHODS Different mucosal biopsies were endoscopically obtained, all samples were immediately fixed with 10% buffered formalin, embedded with paraffin and sectioned serielly. Alterations of p16 and Rb protein in 12 cases of superficial gastritis, 15 atrophic gastritis, 20 atypical hyperplasia and 40 cancerous tissues were detected by the immunohistochemical method (ABC). RESULTS Different degrees of nuclear immunostaining of p16 and Rb occurred on gastric epithelium in different stages of lesions. With the lesions progressing, the positive immunostaining rate of p16 protein had a decreasing tendency (833%→733%→300%→275%), and on the other hand, that of Rb protein had an increasing tendency (250%→467%→600%→675%). A negative correlationship was found between these two parameters in the gastric cancer. Of 40 cases of gastric cancer, a negative relationship was observed in 20 cases. In comparison with both positive (9 cases) and both negative tissues (11 cases), there was a significant difference (500%,225%,275%) (P<005).CONCLUSION Abnormal expression of p16 and Rb plays an important role in gastric carcinogenesis.

Promising key genes associated with tumor microenvironments and prognosis of hepatocellular carcinoma

BACKGROUND Despite significant advances in multimodality treatments,hepatocellular carcinoma(HCC)remains one of the most common malignant tumors.Identification of novel prognostic biomarkers and molecular targets is urgently needed.AIM To identify potential key genes associated with tumor microenvironments and the prognosis of HCC.METHODS The infiltration levels of immune cells and stromal cells were calculated and quantified based on the ESTIMATE algorithm.Differentially expressed genes(DEGs)between high and low groups according to immune or stromal scores were screened using the gene expression profile of HCC patients in The Cancer Genome Atlas and were further linked to the prognosis of HCC.These genes were validated in four independent HCC cohorts.Survival-related key genes were identified by a LASSO Cox regression model.RESULTS HCC patients with a high immune/stromal score had better survival benefits than patients with a low score.A total of 899 DEGs were identified and found to be involved in immune responses and extracellular matrices,147 of which were associated with overall survival.Subsequently,52 of 147 survival-related DEGs were validated in additional cohorts.Finally,ten key genes(STSL2,TMC5,DOK5,RASGRP2,NLRC3,KLRB1,CD5L,CFHR3,ADH1C,and UGT2B15)were selected and used to construct a prognostic gene signature,which presented a good performance in predicting overall survival.CONCLUSION This study extracted a list of genes associated with tumor microenvironments and the prognosis of HCC,thereby providing several valuable directions for the prognostic prediction and molecular targeted therapy of HCC in the future.

ANTITUMOR EFFECTS OF HUMAN IL-15 GENE MODIFIED LUNG CANCER CELL LINE

Human IL15 cDNA fragment, which contains all codons encoding the human IL15 mature protein and signal peptide was transducted into the human lung squmouse cancer cells(PG cells) and murine lung adenocarcinoma cells(LA795 cell lines). Two IL15 highly expressed cell clones PG1 and LA795A were used to inoculate the nude mice and the T739 syngeneic mice respectively. PG1 cell express higher level of class ⅠMHC molecule on their surface than PG cells. It was shown that the modified LA795A tumor cells grew slowly in T739 mice and induced high levels of CTL/NK/LAK activity in vivo as well, compared with the case of inoculation with LA795 or LA795neo. No significant difference in the tumor growth was observed in groups of the nude mice inoculated by PG1, PG and PGneo cells respectively, except the gene modified cells could not show the lung metastasis of tumors. The supernatants derived from the LA795A cell culture could promote CTL/NK/LAK activity from the whole splenocytes and the CD4/CD8deleted splenic cells in vitro. The results indicated that the IL15 gene transfected tumor cells play important roles in the process of antitumor or antitumor metastasis.

A novel gain of function mutant in C-kit gene and its tumorigenesis in nude mice

AIM： To transfect mutant C-kit cDNA at codon 579 into human embryonic kidney cell line to observe its role in the pathogenesis of gastrointestinal stromal tumor （GIST）. METHODS： Eukaryotic expression vectors of pcDNA3- Kit-NW and pcDNA3-Kit-W were constructed. Then pcDNA3-Kit-NW and pcDNA3-Kit-W plasrnids were transfected into human embryonic kidney cell line by Upofectamine. The resistant clone was screened by G418 filtration and identified by sequencing, Western blotting, and immunocytochemical staining. Human embryonic kidney cells were divided into three groups including pcDNA3-Kit-NW, pcDNA3-Kit-W, and vector control groups. Absorbency value with a wavelength of 574 nm was detected by MTT analysis. Mice were injected with three groups of cells. Volume, mass, and histological examinations of the tumors in different groups were measured and compared. RESULTS： The C-kit gene and mutant C-kit gene were successfully cloned into the eukaryotic expression vector pcDNA3, pcDNA3-Kit-NW and pcDNA3-Kit-W were successfully transfected into human embryonic kidney cell line and showed stable expression in this cell line. Cell proliferating activity had significant differences between pcDNA3-Kit-NW and pcDNA3, pcDNA3-Kit- NW and pcDNA3-Kit-W （P〈0.05）, respectively. Tumors were only observed in nude mice implanted with cells transfected with pcDNA3-Kit-NW. CONCLUSION： Mutation of C-kit gene increases the proliferation activity of human cells and plays an important role in the malignant transformation of GIST.

Gene expression and MR diffusion-weighted imaging after chemoembolization in rabbit liver VX-2 tumor model

AIM: To investigate the dynamic characteristics and the correlation between PCNA, Bax, nm23, E-cadherin expression and apparent diffusion coefficient (ADC) on MR diffusion-weighted imaging (DWI) after chemoembolization in rabbit liver VX-2 tumor model. METHODS: Forty New Zealand rabbit liver VX-2 tumor models were included in the study. DWI was carried out periodically after chemoembolization. All VX-2 tumor samples in each group were examined by histopathology and Strept Avidin-Biotin Complex (SABC) immunohistochemical staining. RESULTS: The PCNA expression index in VX-2 tumors was higher than in the normal parenchyma around the tumor (P < 0.001). Nm23, Bax or E-caderin expression index in VX-2 tumors were lower than in the normal parenchyma around the tumor (all P < 0.001). PCNAand nm23 expression in the VX-2 tumor periphery first increased and then decreased (P < 0.001 and P = 0.03, respectively), while the expression of Bax and E-cadherin before and after chemoembolization was insignificant. When b-value was 100 s/mm2, there was a linear correlation between PCNA expression and ADC in the area of VX-2 tumor periphery (P < 0.001), and PCNA expression in VX-2 tumor periphery influenced the ADC. CONCLUSION: The potential of VX-2 tumor infiltrating and metastasizing decreases, while its ability to proliferate increases for a short time after chemoembolization. To some degree, the ADC value indirectly reflects the proliferation of VX-2 tumor cells.

A Comparative Study Between Tumor Blood Vessels and Dynamic Contrast-enhanced MRI for Identifying Isocitrate Dehydrogenase Gene 1(IDH1)Mutation Status in Glioma

Objective Isocitrate dehydrogenase gene(IDH)mutations are associated with tumor angiogenesis and therefore play an important role in glioma management.This study compared the performance of tumor blood vessels counted from contrast-enhanced 3D brain volume(3D-BRAVO)sequence and dynamic contrast-enhanced(DCE)MRI in differentiating IDH1 status in gliomas.Methods Forty-four glioma patients[16 with IDH1 mutant-type(IDH1-MT),28 with IDH1 wild-type(IDH1-WT)]were retrospectively analyzed.A blood vessel entering a tumor was defined as an intratumoral vessel;a blood vessel adjacent to the edge of a tumor was defined as a peritumoral vessel.Combined vessels were defined as the sum of the intratumoral and peritumoral vessels.DCE-derived metrics of tumor were normalized to the contralateral normal-appearing white matter.Results Intratumoral,peritumoral,and combined tumor blood vessels were all significantly different between IDH1-MT and IDH1-WT gliomas,and the range of area under curves(AUCs)was 0.816–0.855.For DCE-derived parameters,cerebral blood volume,cerebral blood flow,mean transit time,and volume transfer constant were significantly different between IDH1-MT and IDH1-WT gliomas,and the range of AUCs was 0.703–0.756.Combined vessels possessed the best performance for identifying IDH1 mutations in gliomas(AUC:0.855,sensitivity:0.857,specificity:0.812,P<0.001).Conclusion The number of tumor blood vessels has comparable diagnostic performance with DCE-derived parameters for differentiating IDH1 mutations and can serve as a potential imaging biomarker to reflect IDH1 mutations in gliomas.

Relationship between hepatitis B virus associated primary hepatocellular carcinoma and alteration of tumor suppressor gene p53

Objective: To explore the changes and significance of tumor suppressor gene p53 in primary hepatocellu-lar carcinoma (PHC ) with hepatitis B virus (HBV ) infection. Methods: Tumor tissues and surrounding nontumortissues of sixteen PHC cases were studied by Southern hybridization to detect the state of HBV-DNA in tissues, byimmunohistochemical staining to determine HBsAg, HBxAg and p53 protein, and by PCR directed sequencing toanalyse the point mutation of p53 gene exons 5 to 8. Results: Among the 16 cases. 13 cases were HBV-DNA posi-tive, 10 tumor cases and 13 nontumor tissues cases HBxAg positive, and 9 cases posltive for p53 protein. The se-quencing of p53 gene point mutation was found in 5 cases, only one of which was sited at codon 249 G to T. Con-clusion: The mutation of p53 gene codon 249 is infrequent in HBV related PHC,indicating the accumulation of p53protein in cells may be associated with expression of HBxAg. HBxAg binding to p53 protein and inactivation of p53function play important roles in the development of PHC.

Aberrant methylation of the 3q25 tumor suppressor gene PTX3 in human esophageal squamous cell carcinoma

AIM:To identify the novel methylation-silenced gene pentraxin 3(PTX3) in esophageal squamous cell carcinoma(ESCC).METHODS:PTX3 mRNA expression was examined in six human ESCC cell lines,one human immortalized normal esophageal epithelial cell line,primary ESCC tumor tissue,and paired adjacent nontumor tissue using reverse transcription polymerase chain reaction(RTPCR).Semi-quantitative immunohistochemistry was used to examine cellular localisation and protein levels.Methylation specific PCR and bisulphite genomic sequencing were employed to investigate the methylation of the candidate gene.RESULTS:In the majority of ESCC cell lines,we found that PTX3 expression was down-regulated due to gene promoter hypermethylation,which was further confirmed by bisulphite genomic sequencing.Demethylation treatment with 5-aza-2'-deoxycytidine restored PTX3 mRNA expression in ESCC cell lines.Methylation was more common in tumor tissues(85%) than in adjacent nontumor tissues(25%)(P < 0.01).CONCLUSION:PTX3 is down-regulated through promoter hypermethylation in ESCC,and could potentially serve as a biomarker of ESCC.

Hypermethylation of tumor suppressor and tumor-related genes in neoplastic and non-neoplastic gastric epithelia

A number of tumor suppressor and tumor-related genes exhibit promoter hypermethylation with resultant gene silencing in human cancers.The frequencies of methylation differ among genes and genomic regions within CpG islands in different tissue types.Hypermethylation initially occurs at the edge of CpG islands and spreads to the transcription start site before ultimately shutting down gene expression.When the degree of methylation was quantitatively evaluated in neoplastic and non-neoplastic gastric epithelia using DNA microarray analysis,highlevel methylation around the transcription start site appeared to be a tumor-specific phenomenon,although multiple tumor suppressor genes became increasingly methylated with patient age in non-neoplastic gastric epithelia.Quantitative analysis of DNA methylation is a promising method for both cancer diagnosis and risk assessment.

THE CLINICAL SIGNIFICANCE OF TUMOR ANGIOGENESIS AND INVASIVENESS-RELATED GENE EXPRESSIONS IN GASTRIC CANCER

Objective: To investigate the correlation among tumor angiogenesis, expressions of p53, nm23-I1, CD44v6, c-erbB-2 proteins and biological behavior and clinical outcome of gastric cancer. Methods: The intratumoral microvessel density (MVD) and expressions of p53, nm23-H1, CD44v6, c-erbB-2 were analyzed semiquantitively by immunohistochemical staining (S-P) of 59 paraffin-embedded gastric tumor specimens that were radically resected at the Department of surgery, Beijing Institute for Cancer Research, between January 1990 and December 1992. The median follow-up period was 75 month (range: 60~96 months). The significdance of these indicators was analyzed retrospectively. Results: MVD for tumors with lymph node metastasis and vascular invasion was significantly higher than those without (P=0.0168 and 0.0176, respectively). The levels of p53, CD44v6, c-erbB-2 expression were significantly higher in the groups of lymph node metastasis, serosal infiltration and vascular invasion than in those without. All differences reached the statistically significant levels (P<0.01~<0.05). The low expression of nm23-H1 was negatively correlated with lymph node metastasis, serosal infiltration and vascular invasion (P<0.01; <0.05 and <0.01, respectively). Univariate analysis showed that the overall survival of patients with higher MVD, or overexpressions of p53, CD44v6, c-erbB-2, or low expression of nm23-H1 were significantly worse than those with opposite conditions (P=0.0214, 0.0062, 0.0045, 0.0159, and 0.0162, respectively). Multivariate analysis showed that expression of p53 in this series was an independent prognostic indicator. Conclusion: The data suggested that the above-mentioned factors might be helpful in evaluating the metastatic potential of gastric cancer and making more effective assessment of prognosis for individual patient. Further study with larger samples and prospective investigation of these results would be worthwhile.