Epidermal growth factor (EGF) is produced primarily by Leydig cells of human testis. Expression of the EGF gene was assessed in mouse testis during the course of sexual maturation by the application of the RT-PCR meth...Epidermal growth factor (EGF) is produced primarily by Leydig cells of human testis. Expression of the EGF gene was assessed in mouse testis during the course of sexual maturation by the application of the RT-PCR method and the use of specific oligonucleotide primers. Testis EGF mRNA content increased with the developmental age of the mice, i.e., day 15 < day 30 < day 45 postnatal. The expression of the EGF gene appears to correlate with maturation of the testis and proliferation of Leydig cells.展开更多
AIM: To determine whether diminished levels of epidermal growth factor (EGF) were present in neo-natal rats with intestinal injury and related with the degree of intestinal injury, so we modeled a model in neo-natal r...AIM: To determine whether diminished levels of epidermal growth factor (EGF) were present in neo-natal rats with intestinal injury and related with the degree of intestinal injury, so we modeled a model in neo-natal rats of intestinal injury and to examine the dynamic levels of EGF on injury of intestine.METHODS: One-day-old Wistar rat pups received an intraperitoneally injection with 4 mg/kg lipopolysaccharide (LPS), followed by collection of ileum tissue at 1, 3, 6, 12,and 24 h following LPS administration. The ileum was for histological evaluation of NEC and for measurements of EGF using ABC-ELISA. The correlation between the degree of intestinal injury and levels of EGF was determined. RESULTS: The LPS-injected pups also showed a significant increase in injury scores at 1, 3, 6, 12, and 24 h [respectively, (1.08±0.61), (1.63±0.84), (1.95±0.72), (2.42±0.43)and (2.21±0.53)] vsthe control (0.12±0.17) (P＜0.01).EGF levels at 1, 3, 6, 12 h [respectively, (245.6±49.0), (221.4±39.0), (223.4±48.1), (246.0±46.6)] pg/mg were significantly loss than the control (275.6±50.4) pg/mg (P＜0.05). There was a significant negative correlation between the EGF levels and the grade of intestinal injury within 24 h (P＜0.05).CONCLUSION: Neo-natal rats with intestinal injury have significantly lower levels of ileum EGF. Reduced levels of this growth factor might be related to the pathogenesis of NEC.展开更多
AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage ...AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-（18F）fluoro-D- glucose （FDG） autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS： The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-n, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic band- ing analysis showed that the diploid （2n） cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION： The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.展开更多
Objective： By studying the influence of low-dose total body irradiation to proliferating cell nuclear antigens （PCNA）, epidermal growth factor receptor （EGFR）, erythropoietin （EPO） and vascular endothelial grow...Objective： By studying the influence of low-dose total body irradiation to proliferating cell nuclear antigens （PCNA）, epidermal growth factor receptor （EGFR）, erythropoietin （EPO） and vascular endothelial growth factor receptor （VEGFR） of tumor tissues in mice bearing S180 sarcoma, to further explore the mechanism of low doses radiation. Methods：S180 sarcoma cells were implanted subcutaneously into 58 male Kunming mice. Randomly these mice were divided into sham-irradiation （S） group and low-dose radiation （LDR） group. 12 days after implantation, the mice in LDR group were once delivered 75 mGy total-body ^60Co y-ray irradiation, while the mice in S group were left without irradiation. Then the mice in LDR group were executed at 6 h （LDR-6h group）, 12 h （LDR-12 h group）, 24 h （LDR-24 h group）, 48 h （LDR-48 h group） and 72 h （LDR-72h group） after irradiation. Tumor tissues were weighed and histological observed. Immunohistochemical staining was used to detect the expression of PCNA, VEGF, EPO and VEGFR of tumor tissues. Results： Though there was no significant difference between LDR group and S group in tumor weight, after irradiation the expression of PCNA and EPO of tumor tissues in LDR group decreased with time. LDR-24h, LDR-48h and LDR-72h groups were all statistically significantly different from S group. The expression of EGFR and VEGFR also decreased, and LDR-24h group was the lowest （P 〈 0.05）. Conclusion： Seventy-two h after low-dose total body irradiation, there was no significant change in tumor size of mice bearing S180 sarcoma. Low-dose total body radiation decreased the expression of PCNA inhibiting tumor growth; reduced the expression of EGFR in tumor tissue impacting the signal transduction of tumor cells. The study also indicated that low-dose total body irradiation, within a certain period of time, can decrease the expression of hypoxia factor EPO and VEGFR, which may improve the situation of tumor hypoxia and radiosensitivity of tumor itself.展开更多
The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal st...The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.展开更多
Objective:To explore the inhibitory effect of moxibustion on tumor growth and metastasis, and also its possible mechanism, in gastric tumor-bearing rats by investigating the expressions of vascular endothelial growth ...Objective:To explore the inhibitory effect of moxibustion on tumor growth and metastasis, and also its possible mechanism, in gastric tumor-bearing rats by investigating the expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF). Methods:Fifty healthy Sprague-Dawley (SD) rats (half male and half female) were routinely housed for 1 week. A total of 20 rats were randomly divided into a blank group and a sham operation group, with 10 rats in each group. The remaining 30 rats were used to make gastric cancer models by implantation of ascites-type Walker-256 cancer cells. After successful modeling, rats were randomly divided into a model group, a moxibustion group and an infrared group, with 10 rats in each group. From the day of modeling, the body weight of each group was weighed every 4 days. Warm moxibustion was alternately performed at two-group acupoints [Zhongwan (CV 12), Guanyuan (CV 4) and bilateral Zusanli (ST 36) in one group, and bilateral Pishu (BL 20) and Weishu (BL 21) in another group] in the moxibustion group. The body surface projection area of the stomach was irradiated with short-wave infrared rays in the infrared group, once a day, 20 min per time for 21 d. At the end of the treatment, the gastric tumor was completely dissected, and the tumor volume and tumor growth inhibition rate were calculated. Then the gastric tumor cell metastasis was recorded. The levels of VEGF and EGF in rat gastric tumor tissues were determined by enzyme-linked immunosorbent assay (ELISA). Results:Compared with the blank group, the body weight of the model group decreased significantly after modeling (P<0.05);compared with the model group, the rats in the moxibustion group had increased body weight during the middle and late stages (bothP<0.05). The tumor volumes of rats in the moxibustion group and the infrared group were smaller than the volume in the model group (bothP<0.05). The tumor growth inhibition rate in the moxibustion group was significantly higher than that in the infrared group (P<0.05). The case number of tumor metastasis in the moxibustion group was smaller than that in the model group and the infrared group. The VEGF level in the tumor tissues of the model group was statistically significantly higher than that in the blank group (P<0.05). Compared with the model group, the VEGF levels in the moxibustion group and the infrared group were statistically significantly lower (bothP<0.05). The EGF levels in the tumor tissues of the model group was statistically significantly lower than that in the blank group (P<0.05);compared with the model group, the EGF levels in the moxibustion group and the infrared group were statistically significantly increased (bothP<0.05). Conclusion:Moxibustion can increase the body weight, inhibit the tumor growth, invasion and metastasis in gastric tumor-bearing rats, which may be related to the regulation of VEGF and EGF expressions in tumor tissues.展开更多
文摘Epidermal growth factor (EGF) is produced primarily by Leydig cells of human testis. Expression of the EGF gene was assessed in mouse testis during the course of sexual maturation by the application of the RT-PCR method and the use of specific oligonucleotide primers. Testis EGF mRNA content increased with the developmental age of the mice, i.e., day 15 < day 30 < day 45 postnatal. The expression of the EGF gene appears to correlate with maturation of the testis and proliferation of Leydig cells.
文摘AIM: To determine whether diminished levels of epidermal growth factor (EGF) were present in neo-natal rats with intestinal injury and related with the degree of intestinal injury, so we modeled a model in neo-natal rats of intestinal injury and to examine the dynamic levels of EGF on injury of intestine.METHODS: One-day-old Wistar rat pups received an intraperitoneally injection with 4 mg/kg lipopolysaccharide (LPS), followed by collection of ileum tissue at 1, 3, 6, 12,and 24 h following LPS administration. The ileum was for histological evaluation of NEC and for measurements of EGF using ABC-ELISA. The correlation between the degree of intestinal injury and levels of EGF was determined. RESULTS: The LPS-injected pups also showed a significant increase in injury scores at 1, 3, 6, 12, and 24 h [respectively, (1.08±0.61), (1.63±0.84), (1.95±0.72), (2.42±0.43)and (2.21±0.53)] vsthe control (0.12±0.17) (P＜0.01).EGF levels at 1, 3, 6, 12 h [respectively, (245.6±49.0), (221.4±39.0), (223.4±48.1), (246.0±46.6)] pg/mg were significantly loss than the control (275.6±50.4) pg/mg (P＜0.05). There was a significant negative correlation between the EGF levels and the grade of intestinal injury within 24 h (P＜0.05).CONCLUSION: Neo-natal rats with intestinal injury have significantly lower levels of ileum EGF. Reduced levels of this growth factor might be related to the pathogenesis of NEC.
文摘AIM： TO characterize a culture model of rat CCA cells, which were derived from a transplantable TTA-induced CCA and designated as Chang Gung CCA （CGCCA）. METHODS： The CGCCA cells were cultured at in vitro passage 12 times on a culture dish in DMEM medium. To measure the doubling time, 103 cells were plated in a 96-well plate containing the growth medium. The cells were harvested 4 to 10 d after seeding, and a standard MTT assay was used to measure the growth. The phenotype of CACCA cell and xenograft was determined by immunohistochemical study. We also determine the chromosomal alterations of CGCCA, G-banding and spectral karyotyping studies were performed. The CGCCA cell line was transplanted into the nude mice for examining its tumorigenicity. 2-Deoxy-2-（18F）fluoro-D- glucose （FDG） autoradiography was also performed to evaluate the FDG uptake of the tumor xenograft. RESULTS： The doubling time for the CGCCA cell line was 32 h. After transplantation into nude mice, FDG autoradiography showed that the tumors formed at the cell transplantation site had a latency period of 4-6 wk with high FDG uptake excluding necrosis tissue. Moreover, immunohistochemical staining revealed prominent cytoplasmic expression of c-erb-B2, CK19, c-Met, COX-n, EGFR, MUC4, and a negative expression of K-ras. All data confirmed the phenotypic features of the CGCCA cell line coincide with the xenograft mice tumors, indicating cells containing the tumorigenicity of CCA originated from CCA. In addition, karyotypic band- ing analysis showed that the diploid （2n） cell status combines with ring and giant rod marker chromosomes in these clones; either both types simultaneously appeared or only one type of marker chromosome in a pair appeared in a cell. The major materials contained in the marker chromosome were primarily identified from chromosome 4. CONCLUSION： The current CGCCA cell line may be used as a non-K-ras effect CCA model and to obtain information and reveal novel pathways for CCA. Further applications regarding tumor markers or therapeutic targeting of CCA should be addressed accordingly.
基金Supported by a grant from the National Natural Scientific Foundation of China (No: 30030781)
文摘Objective： By studying the influence of low-dose total body irradiation to proliferating cell nuclear antigens （PCNA）, epidermal growth factor receptor （EGFR）, erythropoietin （EPO） and vascular endothelial growth factor receptor （VEGFR） of tumor tissues in mice bearing S180 sarcoma, to further explore the mechanism of low doses radiation. Methods：S180 sarcoma cells were implanted subcutaneously into 58 male Kunming mice. Randomly these mice were divided into sham-irradiation （S） group and low-dose radiation （LDR） group. 12 days after implantation, the mice in LDR group were once delivered 75 mGy total-body ^60Co y-ray irradiation, while the mice in S group were left without irradiation. Then the mice in LDR group were executed at 6 h （LDR-6h group）, 12 h （LDR-12 h group）, 24 h （LDR-24 h group）, 48 h （LDR-48 h group） and 72 h （LDR-72h group） after irradiation. Tumor tissues were weighed and histological observed. Immunohistochemical staining was used to detect the expression of PCNA, VEGF, EPO and VEGFR of tumor tissues. Results： Though there was no significant difference between LDR group and S group in tumor weight, after irradiation the expression of PCNA and EPO of tumor tissues in LDR group decreased with time. LDR-24h, LDR-48h and LDR-72h groups were all statistically significantly different from S group. The expression of EGFR and VEGFR also decreased, and LDR-24h group was the lowest （P 〈 0.05）. Conclusion： Seventy-two h after low-dose total body irradiation, there was no significant change in tumor size of mice bearing S180 sarcoma. Low-dose total body radiation decreased the expression of PCNA inhibiting tumor growth; reduced the expression of EGFR in tumor tissue impacting the signal transduction of tumor cells. The study also indicated that low-dose total body irradiation, within a certain period of time, can decrease the expression of hypoxia factor EPO and VEGFR, which may improve the situation of tumor hypoxia and radiosensitivity of tumor itself.
基金supported by the National Natural Science Foundation of China(31330049,31221064)National Basic Research Program of China(2011CB943803,2011CBA01104,2010CB833706)to Chen Ye-Guang
文摘The remarkable ability of rapid self-renewal makes the intestinal epithelium an ideal model for the study of adult stem cells. The intestinal epithelium is organized into villus and crypt, and a group of intestinal stem cells located at the base of crypt are responsible for this constant self-renewal throughout the life. Identification of the intestinal stem cell marker Lgr5, isolation and in vitro culture of Lgr5+ intestinal stem cells and the use of transgenic mouse models have significantly facilitated the studies of intestinal stem cell homeostasis and differentiation, therefore greatly expanding our knowledge of the regulatory mechanisms underlying the intestinal stem cell fate determination. In this review, we summarize the current understanding of how signals of Wnt, BMP, Notch and EGF in the stem cell niche modulate the intestinal stem cell fate.
文摘Objective:To explore the inhibitory effect of moxibustion on tumor growth and metastasis, and also its possible mechanism, in gastric tumor-bearing rats by investigating the expressions of vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF). Methods:Fifty healthy Sprague-Dawley (SD) rats (half male and half female) were routinely housed for 1 week. A total of 20 rats were randomly divided into a blank group and a sham operation group, with 10 rats in each group. The remaining 30 rats were used to make gastric cancer models by implantation of ascites-type Walker-256 cancer cells. After successful modeling, rats were randomly divided into a model group, a moxibustion group and an infrared group, with 10 rats in each group. From the day of modeling, the body weight of each group was weighed every 4 days. Warm moxibustion was alternately performed at two-group acupoints [Zhongwan (CV 12), Guanyuan (CV 4) and bilateral Zusanli (ST 36) in one group, and bilateral Pishu (BL 20) and Weishu (BL 21) in another group] in the moxibustion group. The body surface projection area of the stomach was irradiated with short-wave infrared rays in the infrared group, once a day, 20 min per time for 21 d. At the end of the treatment, the gastric tumor was completely dissected, and the tumor volume and tumor growth inhibition rate were calculated. Then the gastric tumor cell metastasis was recorded. The levels of VEGF and EGF in rat gastric tumor tissues were determined by enzyme-linked immunosorbent assay (ELISA). Results:Compared with the blank group, the body weight of the model group decreased significantly after modeling (P<0.05);compared with the model group, the rats in the moxibustion group had increased body weight during the middle and late stages (bothP<0.05). The tumor volumes of rats in the moxibustion group and the infrared group were smaller than the volume in the model group (bothP<0.05). The tumor growth inhibition rate in the moxibustion group was significantly higher than that in the infrared group (P<0.05). The case number of tumor metastasis in the moxibustion group was smaller than that in the model group and the infrared group. The VEGF level in the tumor tissues of the model group was statistically significantly higher than that in the blank group (P<0.05). Compared with the model group, the VEGF levels in the moxibustion group and the infrared group were statistically significantly lower (bothP<0.05). The EGF levels in the tumor tissues of the model group was statistically significantly lower than that in the blank group (P<0.05);compared with the model group, the EGF levels in the moxibustion group and the infrared group were statistically significantly increased (bothP<0.05). Conclusion:Moxibustion can increase the body weight, inhibit the tumor growth, invasion and metastasis in gastric tumor-bearing rats, which may be related to the regulation of VEGF and EGF expressions in tumor tissues.
