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...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.展开更多
The proteins encoded by oncogene were thought to be tumor associated antigen. The protein P110 in MGC803, a human gastric cancer cell line, was purified as immunogen. The IgY to the gastric cancer was extracted from e...The proteins encoded by oncogene were thought to be tumor associated antigen. The protein P110 in MGC803, a human gastric cancer cell line, was purified as immunogen. The IgY to the gastric cancer was extracted from eggs laid by immunized hen. The IgY could react immunohistochemically with gastric cancers. Positive staining rates of PAF were 80% in gastric cancers and markedly higher than in cancers of other organs and normal gastric tissue. The IgY-Ricin A was synthesized by the IgY conjugated with Ricin A- chain. TCID50 of MGC803 treated by the IgY-Ricin A was 0. 01 mg/ml and markedly lower than other cell. These results showed the IgY-Ricin A were able to react with gastric cancers selectively.展开更多
The Intrinsic structural disorder (ISD) of native EWS and its fusion oncogenic proteins, including EWS/FliI, EWS/ATF1 and EWS/ZSG, was estimated by different Predictors. The ISD difference between the wild type and th...The Intrinsic structural disorder (ISD) of native EWS and its fusion oncogenic proteins, including EWS/FliI, EWS/ATF1 and EWS/ZSG, was estimated by different Predictors. The ISD difference between the wild type and the oncogenic fusions found in the CTD is due to the fusion partner, usually a transcription factor (TF). A disordered region was found in the sequence (AA 132 - 156) of the NTD (EAD) of EWS, consisting of the longest region free of Y motifs. The IQ domain (AA 258 - 280), a Y-free region, flanked by two Y-boxes, is also disordered by all used Predictors. The EWS functional regions RGG1, RGG2 and RGG3 are predominantly disordered. A strong dependence was found between the structure of EWS protein and its oncogenic fusions, and their estimated ISD. The oncogenic function of the fusions is related to a decreased ISD in the CTD, due to the fused TF. The Predictors shown that the different isoforms have similar profiles, shifted with some amino acids, due to the translocations. On the bases of the prediction results, an analysis was made of the EWS sequence and its functional regions with increased ISD to make a relationship sequence-disorder-function that could be helpful in the design of antitumor agents against the corresponding malignances.展开更多
AIM To study the effect of phosphorylation ofMAPK and Stat3 and the expression of c-fos andc-jun proteins on hepatocellular carcinogenesisand their clinical significance.METHODS SP immunohistochemistry was usedto dete...AIM To study the effect of phosphorylation ofMAPK and Stat3 and the expression of c-fos andc-jun proteins on hepatocellular carcinogenesisand their clinical significance.METHODS SP immunohistochemistry was usedto detect the expression of p42/44MAPK, p-Stat3,c-fos and c-jun proteins in 55 hepatocellularcarcinomas (HCC) and their surrounding livertissues.RESULTS The positive rates and expressionlevels of p42/44MAPK, p-Stat3, c-fos and c-junproteins in HCCs were significantly higher thanthose in pericarcinomatous liver tissues (PCLT).A positive correlation was observed between theexpression of p42/44MAPK and c-fos proteins, andbetween p-Stat3 and c-jun, but there was nosignificant correlation between p42/44MAPK and p-Stat3 in HCCs and their surrounding livertissues.CONCLUSION The abnormalities of Ras/Rat/MAPK and JAKs/ Stat3 cascade reaction maycontribute to malignant transformation ofhepatocytes. Hepatocytes which are positive forp42/ 44MAPK, c-fos or c-jun proteins may bepotential malignant pre-cancerous cells.Activation of MAPK and Stat3 proteins may be anearly event in hepatocellular carcinogenesis.展开更多
Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a gr...Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a group of RNA-binding proteins called "Adenylate-Uridylate-rich elements binding proteins"(AUBPs)control mRNA stability or translation through their binding to AU-rich elements enriched in the 3'UTRs of inflammation-and cancer-associated mRNA transcripts. AUBPs play a central role in the recruitment of target mRNAs into small cytoplasmic foci called Processing-bodies and stress granules(also known as P-body/SG). Alterations in the expression and activities of AUBPs and Pbody/SG assembly have been observed to occur with colorectal cancer(CRC)progression, indicating the significant role AUBP-dependent post-transcriptional regulation plays in controlling gene expression during CRC tumorigenesis.Accordingly, these alterations contribute to the pathological expression of many early-response genes involved in prostaglandin biosynthesis and inflammation,along with key oncogenic pathways. In this review, we summarize the current role of these proteins in CRC development. CRC remains a major cause of cancer mortality worldwide and, therefore, targeting these AUBPs to restore efficient post-transcriptional regulation of gene expression may represent an appealing therapeutic strategy.展开更多
Objective:To explore the expressions of c-fos and c-myc in skin lesion of cutaneous squamous cell carcinoma(CSCC).Methods:Using retrospective analysis.73 cases of CSCC were selected from Department of Dermatology,the ...Objective:To explore the expressions of c-fos and c-myc in skin lesion of cutaneous squamous cell carcinoma(CSCC).Methods:Using retrospective analysis.73 cases of CSCC were selected from Department of Dermatology,the Second Affiliated Hospital of Xi'an Jiaotong University.which were removed between January 2000 and January 2012.It was considered as experimental group.Meanwhile.11 cases of normal skin specimens of non tumor patients were selected as control group.The expression level of c-fos and c-myc was compared in the two groups.Results:The expressions of c-fos[72.60%(53/73)]and c-myc[83.56%(61/73)]in experimental group were statistically significant(P≤0.05)compared with control group(0%).Expression of c-myc protein was negatively related to differentiation of CSCC.The difference was statistically significant(X^2=7.26.P=0.001<0.05).While expression of c-fos protein was positively related to differentiation of CSCC.which was statistically significant(X^2=7.47,P=0.0012<0.025).Conclusions:The expression level of c-fos and c-myc can be used as an importan indicator of CSCC differentiation,and it has closely connection with the differentiated degree,which can guide clinical prognosis.展开更多
PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expr...PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.展开更多
Sustained expression of the Spi-1/PU.1 and Fli-1 oncoproteins blocks globin gene activation in mouse erythroleukemia cells; however, only Spi-1/PU.1 expression inhibits the inclusion of exon 16 in the mature 4.1R mRNA...Sustained expression of the Spi-1/PU.1 and Fli-1 oncoproteins blocks globin gene activation in mouse erythroleukemia cells; however, only Spi-1/PU.1 expression inhibits the inclusion of exon 16 in the mature 4.1R mRNA. This splicing event is crucial for a functional 4.1R protein and, therefore, for red blood cell membrane integrity. This report demonstrates that Spi-1/PU.1 downregulation induces the activation of TRIM10/hematopoietic RING finger 1 （HERF1）, a member of the tripartite motif （TRIM）/RBCC protein family needed for globin gene transcription. Additionally, we demonstrate that TRIM10/HERF1 is required for the regulated splicing of exon 16 during late erythroid differentia- tion. Using inducible overexpression and silencing approaches, we found that： （1） TRIM10/HERF1 knockdown inhibits hemoglobin production and exon splicing and triggers cell apoptosis in dimethylsulfoxide （DMSO）-induced cells; （2） TRIM10/HERF1 upregulation is required but is insufficient on its own to activate exon retention; （3） Fli-1 has no effect on TRIM10/HERFI expression, whereas either DMSO-induced downregulation or shRNA-knockdown of Spi-I/PU.I expression is sufficient to activate TRIM10/HERF1 expression; and （4） Spi-1/PU.1 knockdown triggers both the transcription and the splicing events independently of the chemical induction. Altogether, these data indicate that primary Spi-1/PU.1 downregulation acts on late erythroid differentiation through at least two pathways, one of which requires TRIM10/HERF1 upregulation and parallels the Spi-1/PU.1-induced Fli-1 shutoff regulatory cascade.展开更多
The effect of okadaic acid (OA) on proto-oncogene protein expression of c-neu, c-myc, v-rasH, EGFR, and phosphotyrosine-containing phosphoproteins (P-Tyr) was investigated in rapidly growing (RG) normal human keratino...The effect of okadaic acid (OA) on proto-oncogene protein expression of c-neu, c-myc, v-rasH, EGFR, and phosphotyrosine-containing phosphoproteins (P-Tyr) was investigated in rapidly growing (RG) normal human keratinocytes (NHK) and in SV-40 virally-transformed keratinocytes (SVK) cultured in a growth factor supplemented serum-free medium as assessed by indirect immunofluorescence microscopy. P-Tyr positively stains cell surface antigens (cytoplasm) diffusely at monopolar sites in RG NHK cultures. OA-treatment intensifies cytoplasmic P-Tyr staining at localized monopolar intercellular focal adhesion (IFA) sites with reduced cytoplasmic staining. P-Tyr expression was predominate at IFA sites with little cytoplasmic staining in RG SVK cultures. OA-treatment increased monopolar P-Tyr staining and cytoplasmic staining. OA-treatment in RG NHK cultures intensified cytoplasmic staining of c-myc and EGFR (epidermal growth factor receptor) expression. OA-treatment in RG NHK and SVK cultures intensified c-neu staining at monopolar IFA sites and intensified c-neu staining at both cytoplasmic and bipolar IFA sites in RG SVK cells. OA was especially cytotoxic for SVK cells. RA treatment decreased c-neu expression in RG NHK cultures while TPA treatment has a lesser effect on both cytoplasmic and IFA sites. RA treatment also decreased P-Tyr staining in both NHK and SVK cells. Again, TPA had a lesser inhibitory effect on P-Tyr staining pattern. RA-treatment had a similar effect on P-Tyr staining of RG cultures of a mouse fibroblast cell line. These results confirm the generality of OA, RA and TPA on the regulation of oncogene expression in both normal and malignantly transformed keratinocytes.展开更多
Objective： To examine the expressions of MDM2, P53 and P27 proteins in chronic esophagitis, para-cancer mucosa and esophageal carcinoma. Methods： Immunohistochemistry was used to detect the expressions of MDM2, P53 ...Objective： To examine the expressions of MDM2, P53 and P27 proteins in chronic esophagitis, para-cancer mucosa and esophageal carcinoma. Methods： Immunohistochemistry was used to detect the expressions of MDM2, P53 and P27 proteins in forty-seven patients suffering from chronic esophagitis and eighty-five cases of esophageal carcinoma and corresponding para-cancer mucosa. Flow cytometry（（FCM） was applied to detect the quantities of these proteins expressed in fresh tissues of 48 cases of esophageal cancer and their para-cancer tissues and 24 cases of relative normal mucosa at the surface of cutting edge. Results： Immunohistochemistry results showed that the expressions of the three studied proteins were very similar in the epithelia of chronic esophagitis and para-cancer mucosa （P〉0.05）. Both the qualitative and quantitative studies displayed that the P53 protein had no expression and its accumulations would appear only in the early stages of esophagus canceration while the MDM2 and P27 proteins had different degrees of expressions in cases of normal esophageal mucosa. MDM2 protein markedly increased in the advanced stages of esophageal canceration. A quantitative study showed that the expression of P27 protein had a linearity of decreasing tendency （F=9.132, P=0.002） in the course of esophageal canceration. Conclusion： Chronic esophagitis may be a precancerous lesion. Owing to the changes of the P53 and P27 proteins, we can also conclude that these occur in the early stages of esophagus oncogenesis, however the changes of MDM2 expression may occur in the advanced stage of esophageal canceration.展开更多
Prostate cancer is the second leading cause of cancer deaths in the United States and remains a significant health concern for men throughout the world. Despite the discovery of promising immunotherapeutic strategies,...Prostate cancer is the second leading cause of cancer deaths in the United States and remains a significant health concern for men throughout the world. Despite the discovery of promising immunotherapeutic strategies, curative outcomes remain elusive. We have investigated eosinophils as potential anti-cancer effector cells, and have reported the ability of their toxic granular proteins (MBP, EPO, ECP, EDN) to inhibit prostate tumor cell growth?in vitro. This study investigates the effect of eosinophil MBP extract on the expression of oncogenes p53, bcl-xl, bax, and c-myc, which modulate tumor growth, proliferation, and apoptosis. Briefly, granular proteins were differentially extracted from GRC.014.22 and GRC.014.24, eosinophilic cell lines established in our laboratory from a patient with moderate asthma. Protein extracts were fractionated on Sephadex G-50 columns, and prostate tumor cell lines DU-145, LNCaP, PC-3, and HPC8L (established in our laboratory from a tumor resected from an African American patient) were treated with MBP extracts from the pooled third peaks. Colony formation and monolayer cell growth inhibition assays were used to evaluate the protein’s growth inhibitory activity against prostate tumor cells;and gene expression analyses, to determine p53, bcl-xl, bax, and c-myc oncogene expression. We show that the granular proteins were potent in their action on HPC8L, inhibiting colony formation in a dose-dependent manner. Treated prostate tumor cell lines trended toward apoptosis-induction, as evident in bcl-xl/bax ratios < 1, increased p53 expression, and up or downregulation of c-myc. These preliminary results demonstrate the growth inhibitory potential of eosinophil granular proteins and strongly support the hypothesis that eosinophils modulate the expression of oncogenes associated with prostate tumor proliferation and apoptosis. More importantly, this study offers insights into possible applications of eosinophilic mediators in oncogenic-targeted prostate cancer treatment strategies and demonstrates the potential therapeutic implications of enhancing eosinophilic activity in prostate cancer.展开更多
AIM To investigate hepatocarcinogenesis by detecting the effect of HCV NS 3 protein on P53 protein expression in hepatocellular carcinoma (HCC) and pericarcinomatous liver tissue (PCLT). METHODS The expression of ...AIM To investigate hepatocarcinogenesis by detecting the effect of HCV NS 3 protein on P53 protein expression in hepatocellular carcinoma (HCC) and pericarcinomatous liver tissue (PCLT). METHODS The expression of HCV NS 3 and P53 protein was detected with immunohistochemical technique (SP method) in specimens of HCC and PCLT from 47 patients with negative HBV. RESULTS The positive rate of HCV NS 3 protein was lower in HCC (62%) than in PCLT (83%) ( P <0 025). The better differentiaton of cancer cells, the stronger expression of HCV NS 3 protein ( P <0 025). The positive rate of P53 protein in HCC (81%) was higher than in PCLT (47%) ( P <0 025). The worse differentiaton of cancer cells, the stronger expression of P53 protein ( P <0 05). The P53 protein expression was not correlated with the HCV NS 3 protein expression in HCC ( P >0 5), whereas their expression was closely related to PCLT ( P <0 01), and the expression rate of P53 protein in the cases of positive HCV NS 3 protein was higher than that in the cases of negative HCV NS 3 protein. CONCLUSION HCV NS 3 protein may exert its hepatocarcinogenic effect in early stage on host cells by endogenous pathway which may bring about mutation of p53 gene and transformation of hepatocytes.展开更多
INTRODUCTIONThe esophageal carcinoma is a common malignanttumor in Linzhou City (Linxian) of Henan Provincein northern China.Although the etiology andnatural history of csophageal carcinoma are notclear,a substantial ...INTRODUCTIONThe esophageal carcinoma is a common malignanttumor in Linzhou City (Linxian) of Henan Provincein northern China.Although the etiology andnatural history of csophageal carcinoma are notclear,a substantial amount of evidence has beenprovided to suggest that the development of humanesophageal squamous cell carcinomas (SCC) is amultistage progressive process.An展开更多
基金supported by the Taipei Tzu Chi Hospital through grants from the Buddhist Tzu Chi Medical Foundation under the Numbers TCRD-TPE-111-23(2/3)and TCRD-TPE-113-20,Taipei,Taiwan.
文摘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.
文摘The proteins encoded by oncogene were thought to be tumor associated antigen. The protein P110 in MGC803, a human gastric cancer cell line, was purified as immunogen. The IgY to the gastric cancer was extracted from eggs laid by immunized hen. The IgY could react immunohistochemically with gastric cancers. Positive staining rates of PAF were 80% in gastric cancers and markedly higher than in cancers of other organs and normal gastric tissue. The IgY-Ricin A was synthesized by the IgY conjugated with Ricin A- chain. TCID50 of MGC803 treated by the IgY-Ricin A was 0. 01 mg/ml and markedly lower than other cell. These results showed the IgY-Ricin A were able to react with gastric cancers selectively.
文摘The Intrinsic structural disorder (ISD) of native EWS and its fusion oncogenic proteins, including EWS/FliI, EWS/ATF1 and EWS/ZSG, was estimated by different Predictors. The ISD difference between the wild type and the oncogenic fusions found in the CTD is due to the fusion partner, usually a transcription factor (TF). A disordered region was found in the sequence (AA 132 - 156) of the NTD (EAD) of EWS, consisting of the longest region free of Y motifs. The IQ domain (AA 258 - 280), a Y-free region, flanked by two Y-boxes, is also disordered by all used Predictors. The EWS functional regions RGG1, RGG2 and RGG3 are predominantly disordered. A strong dependence was found between the structure of EWS protein and its oncogenic fusions, and their estimated ISD. The oncogenic function of the fusions is related to a decreased ISD in the CTD, due to the fused TF. The Predictors shown that the different isoforms have similar profiles, shifted with some amino acids, due to the translocations. On the bases of the prediction results, an analysis was made of the EWS sequence and its functional regions with increased ISD to make a relationship sequence-disorder-function that could be helpful in the design of antitumor agents against the corresponding malignances.
文摘AIM To study the effect of phosphorylation ofMAPK and Stat3 and the expression of c-fos andc-jun proteins on hepatocellular carcinogenesisand their clinical significance.METHODS SP immunohistochemistry was usedto detect the expression of p42/44MAPK, p-Stat3,c-fos and c-jun proteins in 55 hepatocellularcarcinomas (HCC) and their surrounding livertissues.RESULTS The positive rates and expressionlevels of p42/44MAPK, p-Stat3, c-fos and c-junproteins in HCCs were significantly higher thanthose in pericarcinomatous liver tissues (PCLT).A positive correlation was observed between theexpression of p42/44MAPK and c-fos proteins, andbetween p-Stat3 and c-jun, but there was nosignificant correlation between p42/44MAPK and p-Stat3 in HCCs and their surrounding livertissues.CONCLUSION The abnormalities of Ras/Rat/MAPK and JAKs/ Stat3 cascade reaction maycontribute to malignant transformation ofhepatocytes. Hepatocytes which are positive forp42/ 44MAPK, c-fos or c-jun proteins may bepotential malignant pre-cancerous cells.Activation of MAPK and Stat3 proteins may be anearly event in hepatocellular carcinogenesis.
基金Supported by the National Institutes of Health/National Cancer Institute Cancer Center Support grant P30 CA168524(DD)supported by a grant of the Geneva Cancer League(Grant no.1711)
文摘Trans-acting factors controlling mRNA fate are critical for the post-transcriptional regulation of inflammation-related genes, as well as for oncogene and tumor suppressor expression in human cancers. Among them, a group of RNA-binding proteins called "Adenylate-Uridylate-rich elements binding proteins"(AUBPs)control mRNA stability or translation through their binding to AU-rich elements enriched in the 3'UTRs of inflammation-and cancer-associated mRNA transcripts. AUBPs play a central role in the recruitment of target mRNAs into small cytoplasmic foci called Processing-bodies and stress granules(also known as P-body/SG). Alterations in the expression and activities of AUBPs and Pbody/SG assembly have been observed to occur with colorectal cancer(CRC)progression, indicating the significant role AUBP-dependent post-transcriptional regulation plays in controlling gene expression during CRC tumorigenesis.Accordingly, these alterations contribute to the pathological expression of many early-response genes involved in prostaglandin biosynthesis and inflammation,along with key oncogenic pathways. In this review, we summarize the current role of these proteins in CRC development. CRC remains a major cause of cancer mortality worldwide and, therefore, targeting these AUBPs to restore efficient post-transcriptional regulation of gene expression may represent an appealing therapeutic strategy.
基金Supported by Natural Science Foundation of Shaanxi Province(Grant No.2018722)
文摘Objective:To explore the expressions of c-fos and c-myc in skin lesion of cutaneous squamous cell carcinoma(CSCC).Methods:Using retrospective analysis.73 cases of CSCC were selected from Department of Dermatology,the Second Affiliated Hospital of Xi'an Jiaotong University.which were removed between January 2000 and January 2012.It was considered as experimental group.Meanwhile.11 cases of normal skin specimens of non tumor patients were selected as control group.The expression level of c-fos and c-myc was compared in the two groups.Results:The expressions of c-fos[72.60%(53/73)]and c-myc[83.56%(61/73)]in experimental group were statistically significant(P≤0.05)compared with control group(0%).Expression of c-myc protein was negatively related to differentiation of CSCC.The difference was statistically significant(X^2=7.26.P=0.001<0.05).While expression of c-fos protein was positively related to differentiation of CSCC.which was statistically significant(X^2=7.47,P=0.0012<0.025).Conclusions:The expression level of c-fos and c-myc can be used as an importan indicator of CSCC differentiation,and it has closely connection with the differentiated degree,which can guide clinical prognosis.
基金support by the Ministerio Educación y CienciaMinisterio de Economía y Competitividad of Spain(until June 2013)
文摘PDRG1 is a small oncogenic protein of 133 residues. In normal human tissues, the p53 and DNA damageregulated gene 1(PDRG1) gene exhibits maximal expression in the testis and minimal levels in the liver. Increased expression has been detected in several tumor cells and in response to genotoxic stress. High-throughput studies identified the PDRG1 protein in a variety of macromolecular complexes involved in processes that are altered in cancer cells. For example, this oncogene has been found as part of the RNA polymerase Ⅱ complex, the splicing machinery and nutrient sensing machinery, although its role in these complexes remains unclear. More recently, the PDRG1 protein was found as an interaction target for the catalytic subunits of methionine adenosyltransferases. These enzymes synthesize S-adenosylmethionine, the methyl donor for, among others, epigenetic methylations that occur on the DNA and histones. In fact, downregulation of S-adenosylmethionine synthesis is the first functional effect directly ascribed to PDRG1. The existence of global DNA hypomethylation, together with increased PDRG1 expression, in many tumor cells highlights the importance of this interaction as one of the putative underlying causes for cell transformation. Here, we will review the accumulated knowledge on this oncogene, emphasizing the numerous aspects that remain to be explored.
文摘Sustained expression of the Spi-1/PU.1 and Fli-1 oncoproteins blocks globin gene activation in mouse erythroleukemia cells; however, only Spi-1/PU.1 expression inhibits the inclusion of exon 16 in the mature 4.1R mRNA. This splicing event is crucial for a functional 4.1R protein and, therefore, for red blood cell membrane integrity. This report demonstrates that Spi-1/PU.1 downregulation induces the activation of TRIM10/hematopoietic RING finger 1 （HERF1）, a member of the tripartite motif （TRIM）/RBCC protein family needed for globin gene transcription. Additionally, we demonstrate that TRIM10/HERF1 is required for the regulated splicing of exon 16 during late erythroid differentia- tion. Using inducible overexpression and silencing approaches, we found that： （1） TRIM10/HERF1 knockdown inhibits hemoglobin production and exon splicing and triggers cell apoptosis in dimethylsulfoxide （DMSO）-induced cells; （2） TRIM10/HERF1 upregulation is required but is insufficient on its own to activate exon retention; （3） Fli-1 has no effect on TRIM10/HERFI expression, whereas either DMSO-induced downregulation or shRNA-knockdown of Spi-I/PU.I expression is sufficient to activate TRIM10/HERF1 expression; and （4） Spi-1/PU.1 knockdown triggers both the transcription and the splicing events independently of the chemical induction. Altogether, these data indicate that primary Spi-1/PU.1 downregulation acts on late erythroid differentiation through at least two pathways, one of which requires TRIM10/HERF1 upregulation and parallels the Spi-1/PU.1-induced Fli-1 shutoff regulatory cascade.
文摘The effect of okadaic acid (OA) on proto-oncogene protein expression of c-neu, c-myc, v-rasH, EGFR, and phosphotyrosine-containing phosphoproteins (P-Tyr) was investigated in rapidly growing (RG) normal human keratinocytes (NHK) and in SV-40 virally-transformed keratinocytes (SVK) cultured in a growth factor supplemented serum-free medium as assessed by indirect immunofluorescence microscopy. P-Tyr positively stains cell surface antigens (cytoplasm) diffusely at monopolar sites in RG NHK cultures. OA-treatment intensifies cytoplasmic P-Tyr staining at localized monopolar intercellular focal adhesion (IFA) sites with reduced cytoplasmic staining. P-Tyr expression was predominate at IFA sites with little cytoplasmic staining in RG SVK cultures. OA-treatment increased monopolar P-Tyr staining and cytoplasmic staining. OA-treatment in RG NHK cultures intensified cytoplasmic staining of c-myc and EGFR (epidermal growth factor receptor) expression. OA-treatment in RG NHK and SVK cultures intensified c-neu staining at monopolar IFA sites and intensified c-neu staining at both cytoplasmic and bipolar IFA sites in RG SVK cells. OA was especially cytotoxic for SVK cells. RA treatment decreased c-neu expression in RG NHK cultures while TPA treatment has a lesser effect on both cytoplasmic and IFA sites. RA treatment also decreased P-Tyr staining in both NHK and SVK cells. Again, TPA had a lesser inhibitory effect on P-Tyr staining pattern. RA-treatment had a similar effect on P-Tyr staining of RG cultures of a mouse fibroblast cell line. These results confirm the generality of OA, RA and TPA on the regulation of oncogene expression in both normal and malignantly transformed keratinocytes.
文摘Objective： To examine the expressions of MDM2, P53 and P27 proteins in chronic esophagitis, para-cancer mucosa and esophageal carcinoma. Methods： Immunohistochemistry was used to detect the expressions of MDM2, P53 and P27 proteins in forty-seven patients suffering from chronic esophagitis and eighty-five cases of esophageal carcinoma and corresponding para-cancer mucosa. Flow cytometry（（FCM） was applied to detect the quantities of these proteins expressed in fresh tissues of 48 cases of esophageal cancer and their para-cancer tissues and 24 cases of relative normal mucosa at the surface of cutting edge. Results： Immunohistochemistry results showed that the expressions of the three studied proteins were very similar in the epithelia of chronic esophagitis and para-cancer mucosa （P〉0.05）. Both the qualitative and quantitative studies displayed that the P53 protein had no expression and its accumulations would appear only in the early stages of esophagus canceration while the MDM2 and P27 proteins had different degrees of expressions in cases of normal esophageal mucosa. MDM2 protein markedly increased in the advanced stages of esophageal canceration. A quantitative study showed that the expression of P27 protein had a linearity of decreasing tendency （F=9.132, P=0.002） in the course of esophageal canceration. Conclusion： Chronic esophagitis may be a precancerous lesion. Owing to the changes of the P53 and P27 proteins, we can also conclude that these occur in the early stages of esophagus oncogenesis, however the changes of MDM2 expression may occur in the advanced stage of esophageal canceration.
文摘Prostate cancer is the second leading cause of cancer deaths in the United States and remains a significant health concern for men throughout the world. Despite the discovery of promising immunotherapeutic strategies, curative outcomes remain elusive. We have investigated eosinophils as potential anti-cancer effector cells, and have reported the ability of their toxic granular proteins (MBP, EPO, ECP, EDN) to inhibit prostate tumor cell growth?in vitro. This study investigates the effect of eosinophil MBP extract on the expression of oncogenes p53, bcl-xl, bax, and c-myc, which modulate tumor growth, proliferation, and apoptosis. Briefly, granular proteins were differentially extracted from GRC.014.22 and GRC.014.24, eosinophilic cell lines established in our laboratory from a patient with moderate asthma. Protein extracts were fractionated on Sephadex G-50 columns, and prostate tumor cell lines DU-145, LNCaP, PC-3, and HPC8L (established in our laboratory from a tumor resected from an African American patient) were treated with MBP extracts from the pooled third peaks. Colony formation and monolayer cell growth inhibition assays were used to evaluate the protein’s growth inhibitory activity against prostate tumor cells;and gene expression analyses, to determine p53, bcl-xl, bax, and c-myc oncogene expression. We show that the granular proteins were potent in their action on HPC8L, inhibiting colony formation in a dose-dependent manner. Treated prostate tumor cell lines trended toward apoptosis-induction, as evident in bcl-xl/bax ratios < 1, increased p53 expression, and up or downregulation of c-myc. These preliminary results demonstrate the growth inhibitory potential of eosinophil granular proteins and strongly support the hypothesis that eosinophils modulate the expression of oncogenes associated with prostate tumor proliferation and apoptosis. More importantly, this study offers insights into possible applications of eosinophilic mediators in oncogenic-targeted prostate cancer treatment strategies and demonstrates the potential therapeutic implications of enhancing eosinophilic activity in prostate cancer.
文摘AIM To investigate hepatocarcinogenesis by detecting the effect of HCV NS 3 protein on P53 protein expression in hepatocellular carcinoma (HCC) and pericarcinomatous liver tissue (PCLT). METHODS The expression of HCV NS 3 and P53 protein was detected with immunohistochemical technique (SP method) in specimens of HCC and PCLT from 47 patients with negative HBV. RESULTS The positive rate of HCV NS 3 protein was lower in HCC (62%) than in PCLT (83%) ( P <0 025). The better differentiaton of cancer cells, the stronger expression of HCV NS 3 protein ( P <0 025). The positive rate of P53 protein in HCC (81%) was higher than in PCLT (47%) ( P <0 025). The worse differentiaton of cancer cells, the stronger expression of P53 protein ( P <0 05). The P53 protein expression was not correlated with the HCV NS 3 protein expression in HCC ( P >0 5), whereas their expression was closely related to PCLT ( P <0 01), and the expression rate of P53 protein in the cases of positive HCV NS 3 protein was higher than that in the cases of negative HCV NS 3 protein. CONCLUSION HCV NS 3 protein may exert its hepatocarcinogenic effect in early stage on host cells by endogenous pathway which may bring about mutation of p53 gene and transformation of hepatocytes.
基金the National Natural Science Foundation of China,No.39840012
文摘INTRODUCTIONThe esophageal carcinoma is a common malignanttumor in Linzhou City (Linxian) of Henan Provincein northern China.Although the etiology andnatural history of csophageal carcinoma are notclear,a substantial amount of evidence has beenprovided to suggest that the development of humanesophageal squamous cell carcinomas (SCC) is amultistage progressive process.An
