Biomedical subjects

Wei-Jian Guo

Publications and source records attributed to Wei-Jian Guo.

11 recordsLinked to original sources

PubMed2006

Mel-18, a polycomb group protein, regulates cell proliferation and senescence via transcriptional repression of Bmi-1 and c-Myc oncoproteins.

Polycomb group (PcG) protein Bmi-1 is an important regulator of cell proliferation. It regulates cellular senescence and proliferation of cells via the transcriptional repression of INK4a/ARF locus and other target genes. Here, we report that Mel-18, a PcG ring finger protein (PCGF) transcriptionally down-regulates Bmi-1. Furthermore, the expression of Bmi-1 and Mel-18 inversely correlates in proliferating and senescent human fibroblasts. Bmi-1 down-regulation by Mel-18 results in accelerated senescence and shortening of the replicative life span in normal human cells. Importantly, using promoter-reporter, chromatin immunoprecipitation, and quantitative real-time primary transcript RT-PCR assays, and an RNA interference approach, we demonstrate that Bmi-1 is a bona fide target of c-Myc oncoprotein. Finally, our data suggest that Mel-18 regulates Bmi-1 expression during senescence via down-regulation of c-Myc. These studies link c-Myc and polycomb function in cell proliferation and senescence.

Binding Sites↗

PubMed2005

Treatment for liver metastases from breast cancer: results and prognostic factors.

AIM: Liver metastases from breast cancer (BCLM) are associated with poor prognosis. Cytotoxic chemotherapy can result in regression of tumor lesions and a decrease in symptoms. Available data, in the literature, also suggest a subgroup of patients may benefit from surgery, but few talked about transcatheter arterial chemoembolization (TACE). We report the results of TACE and systemic chemotherapy for patients with liver metastases from breast cancer and evaluate the prognostic factors. METHODS: Forty-eight patients with liver metastases, from proved breast primary cancer were treated with TACE or systemic chemotherapy between January 1995 and December 2000. Treatment results were assessed according to WHO criteria, along with analysis of prognostic factors for survival using Cox regression model. RESULTS: The median follow-up was 28 mo (1-72 mo). Response rates were calculated for the TACE group and chemotherapy group, being 35.7% and 7.1%, respectively. The difference was significant. The one-, two- and three-year Survival rates for the TACE group were 63.04%, 30.35%, and 13.01%, and those for the systemic chemotherapy group were 33.88%, 11.29%, and 0%. According to univariate analysis, variables significantly associated with survival were the lymph node status of the primary cancer, the clinical stage of liver metastases, the Child-Pugh grade, loss of weight. Other factors such as age, the intervals between the primary to the metastases, the maximal diameter of the liver metastases, the number of liver metastases, extrahepatic metastasis showed no prognostic significances. These factors mentioned above such as the lymph node status of the primary cancer, the clinical stage of liver metastases, the Child-Pugh grade, loss of weight were also independent factors in multivariate analysis. CONCLUSION: TACE treatment of liver metastases from breast cancer may prolong survival in certain patients. This approach offers new promise for the curative treatment of the patients with metastatic breast cancer.

Adult↗

PubMed2005

Prediction of pancreatic cancer by serum biomarkers using surface-enhanced laser desorption/ionization-based decision tree classification.

OBJECTIVE: In order to improve the prognosis of pancreatic cancer patients, it is crucial to explore novel tools for its early diagnosis. Here, we attempted to screen serum biomarkers to distinguish pancreatic cancer from non-cancer individuals. METHODS: 47 serum samples from pancreatic cancer patients, 39 of whom had small surgically resectable cancers, were collected before surgery, and an additional 53 serum samples from age- and sex-matched individuals without cancer were used as controls. The surface-enhanced laser desorption/ionization (SELDI) ProteinChip was applied to analyze serum protein profiling. 54 samples (27 with pancreatic cancer and 27 controls) were analyzed in the training set by a decision tree algorithm to be able to separate pancreatic cancer from controls. A double-blind test was used to determine the sensitivity and specificity of the classification model. RESULTS: A panel of six biomarkers was selected to set up a decision tree as the classification model. The model separated effectively pancreatic cancer from control samples, achieving a sensitivity of 88.9% and a specificity of 74.1%. The double-blind test challenged the model with a sensitivity of 80% and a specificity of 84.6%. CONCLUSION: The SELDI ProteinChip combined with an artificial intelligence classification algorithm shows great potential for the diagnosis of pancreatic cancer.

Adult↗

PubMed2003

Intensity modulated radiation therapy and chemotherapy for locally advanced pancreatic cancer: results of feasibility study.

AIM: To explore whether intensity modulated radiation therapy (IMRT) in combination with chemotherapy could increase radiation dose to gross tumor volume without severe acute radiation related toxicity by decreasing the dose to the surrounding normal tissue in patients with locally advanced pancreatic cancer. METHODS: Twenty-one patients with locally advanced pancreatic cancer were evaluated in this clinical trial. Patients would receive the dose of IMRT from 21Gy to 30Gy in 7 to 10 fractions within two weeks after conventional radiotherapy of 30Gy in 15 fractions over 3 weeks. The total escalation tumor dose would be 51, 54, 57, 60Gy, respectively. 5-fluororacil (5-FU) or gemcitabine was given concurrently with radiotherapy during the treatment course. RESULTS: Sixteen patients who had completed the radiotherapy plan with doses of 51Gy (3 cases), 54Gy (3 cases), 57Gy (3 cases) and 60Gy (7 cases) were included for evaluation. The median levels of CA19-9 prior to and after radiotherapy were 716 U/ml and 255 U/ml respectively (P<0.001) in 13 patients who demonstrated high levels of CA19-9 before radiotherapy. Fourteen patients who suffered from pain could reduce at least 1/3-1/2 amount of analgesic intake and 5 among these patients got complete relief of pain. Ten patients improved in Karnofsky performance status (KPS). The median follow-up period was 8 months and one-year survival rate was 35%. No patient suffered more than grade III acute toxicities induced by radiotherapy. CONCLUSION: Sixty Gy in 25 fractions over 5 weeks with late course IMRT technique combined with concurrent 5-FU chemotherapy can provide a definitely palliative benefit with tolerable acute radiation related toxicity for patients with advanced pancreatic cancer.

Adenocarcinoma↗

PubMed2003

Comparison between chemoembolization combined with radiotherapy and chemoembolization alone for large hepatocellular carcinoma.

AIM: To investigate the efficacy of transcatheter arterial chemoembolization (TACE) combined with radiotherapy for unresectable large hepatocellular carcinoma (HCC). METHODS: From June 1994 to June 1999, a total of 76 patients with large unresectable HCC were treated with TACE followed by external-beam irradiation. 89 patients with large HCC, who underwent TACE alone during the same period, served as the control group. Clinical features, therapeutic modalities, acute effects and survival rates were analyzed and compared between TACE plus irradiation group and TACE alone group. A multivariate analysis of nine clinical variables and one treatment variable (irradiation) was performed by the Cox proportional hazards model. RESULTS: The clinical features and therapeutic modalities except irradiation between the two groups were comparable (P>0.05). The objective response rate (RR) in TACE plus irradiation group was higher than that in TACE alone group (47.4 % vs 28.1 %, P<0.05). The overall survival rates in TACE plus irradiation group (64.0 %, 28.6 %, and 19.3 % at 1, 3, 5 years, respectively) were significantly higher than those in TACE alone group (39.9 %, 9.5 %, and 7.2 %, respectively, P=0.0001). Cox proportional hazards model analysis showed that tumor extension and Child grade were significant and were independent negative predictors of survival, while irradiation was an independent positive predictor of survival. CONCLUSION: TACE combined with radiotherapy is more effective than TACE alone, and is a promising treatment for unresectable large HCC.

Carcinoma, Hepatocellular↗

PubMed2002

Influence of hepatic arterial blockage on blood perfusion and VEGF, MMP-1 expression of implanted liver cancer in rats.

AIM: To investigate the influence of hepatic arterial blockage on blood perfusion of transplanted cancer in rat liver and the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-1 (MMP-1), and to explore the mechanisms involved in transarterial embolization (TAE)-induced metastasis of liver cancer preliminarily. METHODS: Walker 256 carcinosarcoma was transplanted into rat liver to establish the liver cancer model. Hepatic arterial ligation (HAL) was used to block the hepatic arterial blood supply and simulate TAE. Blood perfusion of tumor in control, laparotomy control, and HAL group was analyzed by Hoechst 33342 labeling assay, the serum VEGF level was assayed by ELISA, the expression of VEGF and MMP-1 mRNA was detected by in situ hybridization. RESULTS: Two days after HAL, the number of Hoechst 33342 labeled cells which represent the blood perfusion of tumor directly and hypoxia of tumor indirectly in HAL group decreased significantly compared with that in control group (329+/-29 vs 384+/-19, P<0.01). The serum VEGF level in the HAL group increased significantly as against that of the control group (93 ng.L(-1)+/-44 ng.L(-1) vs 55 ng.L(-1)+/-19 ng.L(-1), P<0.05). The expression of VEGF and MMP-1 mRNA in the tumor tissue of the HAL group increased significantly compared with that of the control and the laparotomy control groups (P<0.05). The blood perfusion data of the tumor, represented by the number of Hoechst 33342 labeled cells, showed a good linear inverse correlation with the serum VEGF level (r=-0.606, P<0.05) and the expression of VEGF mRNA in the tumor tissue ( r =-0.338, P<0.01). CONCLUSION: Blockage of hepatic arterial blood supply results in decreased blood perfusion and increased expression of metastasis-associated genes VEGF and MMP-1 of transplanted liver cancer in rats. Decreased blood perfusion and hypoxia may be the major cause of up-regulated expression of VEGF.

Animals↗

PubMed2002

Effects of ursolic acid and oleanolic acid on human colon carcinoma cell line HCT15.

AIM: Ursolic acid (UA) and oleanolic acid (OA) are triperpene acids having a similar chemical structure and are distributed wildly in plants all over the world. In recent years, it was found that they had marked anti-tumor effects. There is little literature currently available regarding their effects on colon carcinoma cells. The present study was designed to investigate their inhibitory effects on human colon carcinoma cell line HCT15. METHODS: HCT15 cells were cultured with different drugs. The treated cells were stained with hematoxylin-eosin and their morphologic changes observed under a light microscope. The cytotoxicity of these drugs was evaluated by tetrazolium dye assay. Cell cycle analysis was performed by flow cytometry (FCM). Data were expressed as means +/-SEM and Analysis of variance and Student' t-test for individual comparisons. RESULTS: Twenty-four to 72 h after UA or OA 60 micromol/L treatment, the numbers of dead cells and cell fragments were increased and most cells were dead at the 72nd hour. The cytotoxicity of UA was stronger than that of OA. Seventy-eight hours after 30 micromol/L of UA or OA treatment, a number of cells were degenerated, but cell fragments were rarely seen. The IC(50) values for UA and OA were 30 and 60 micromol/L, respectively. Proliferation assay showed that proliferation of UA and OA-treated cells was slightly increased at 24h and significantly decreased at 48 h and 60 h, whereas untreated control cells maintained an exponential growth curve. Cell cycle analysis by FCM showed HCT15 cells treated with UA 30 and OA 60 for 36 h and 72 h gradually accumulated in G(0)/G(1) phase (both drugs P<0.05 for 72 h), with a concomitant decrease of cell populations in S phase (both drugs P<0.01 for 72 h) and no detectable apoptotic fraction. CONCLUSION: UA and OA have significant anti-tumor activity. The effect of UA is stronger than that of OA. The possible mechanism of action is that both drugs have an inhibitory effect on tumor cell proliferation through cell-cycle arrest.

Antineoplastic Agents, Phytogenic↗

PubMedDate not supplied

Octreotide augments the effects of hepatic arterial occlusion in treating a rat liver tumor model.

BACKGROUND/AIMS: To observe if octreotide can augment the effects of hepatic arterial occlusion for transplanted cancer in rat's liver. METHODOLOGY: Walker 256 carcinosarcoma was transplanted into rat's liver to create the liver cancer model. Hepatic arterial ligation was used to block the hepatic arterial blood supply. Rats bearing tumor were divided into three groups: control group, HAL (hepatic arterial ligation) group, and HAL plus octreotide group. Change of tumor volume and tumor growth inhibiting rate after therapy were evaluated. Hoechst 33342 labeling assay was used to analyze the blood perfusion of tumor (the labeled cells' number presenting blood perfusion). Expression of vascular endothelial growth factor and matrix metalloproteinase-1 mRNA was detected by in situ hybridization, and the level of serum vascular endothelial growth factor was assayed by ELISA. RESULTS: Six days after hepatic arterial ligation, the mean tumor volume in control group, HAL group, and HAL plus octreotide group was 0.103 +/- 0.043 cm3, 0.030 +/- 0.018 cm3, and 0.016 +/- 0.005 cm3, respectively. The tumor volume in the two behind groups was smaller than that in the control group (P < 0.01), and the tumor growth-inhibiting rate was 70.8%, and 84.5%, respectively. Compared with the HAL group, the tumor volume in HAL plus octreotide group decreased significantly (P < 0.05). Hoechst 33342 labeled cells' number in control group, HAL group, and HAL plus octreotide group was 369.7 +/- 30.2, 344.1 +/- 26.0, and 323.2 +/- 40.4, respectively. The number in HAL combined with octreotide group decreased significantly compared with that in control group (P < 0.05), which suggested that the blood perfusion of tumor in HAL plus octreotide group decreased significantly. The expression of vascular endothelial growth factor and matrix metalloprotenase-1 mRNA decreased slightly, but not significantly in HAL plus octreotide group compared with that in HAL group (P > 0.05). CONCLUSIONS: The results suggest that octreotide can promote the effects of hepatic arterial occlusion therapy for transplanted cancer in rat's liver. Decreasing the blood perfusion of tumor after hepatic arterial blockage maybe one of its major mechanisms.

Animals↗

PubMedDate not supplied

The long-term efficacy of combined chemoembolization and local irradiation in the treatment of patients with large hepatocellular carcinoma.

BACKGROUND/AIMS: To investigate the effects and toxicity of combined transcatheter arterial chemoembolization and local radiotherapy for patients with unresectable hepatocellular carcinoma. METHODOLOGY: From June 1994 to June 1999, 28 patients with unresectable hepatocellular carcinoma (the largest dimension of tumor ranged from 3 to 10 cm) were treated with transcatheter arterial chemoembolization followed by local irradiation. Response was assessed by computed tomography scan and ultrasound, together with serum alpha-fetoprotein level in cases with increased baseline values. Complications associated with treatment were monitored. Cumulative survival was determined by Kaplan-Meier method from the first day of treatment. RESULTS: An objective response (reduction of tumor area greater than 50%) was achieved in 57.0% of the cases. In 63.0% of the cases with increased alpha-fetoprotein values, alpha-fetoprotein level underwent a marked reduction (more than 50%). The cumulative survival rates at 1, 3, and 5 years were 81.9%, 42.4%, and 21.2%, respectively (median survival, 31 months, 95% CI: 27.8-34.2 months). The combination therapy was generally well tolerated. CONCLUSIONS: The results suggest that combined transcatheter arterial chemoembolization with local radiotherapy is an effective and safe treatment for unresectable hepatocellular carcinoma. Further study is required to compare the therapeutic efficacy of this regimen to transcatheter arterial chemoembolization or radiotherapy alone.

Adult↗

PubMedDate not supplied

Large primary liver cancer treated by chemoembolization combined with radiotherapy successfully.

For unresectable primary liver cancer, transcatheter arterial chemoembolization is the most effective method in reducing the size of tumor and become the most popular forms in Asia, but, it is not a curative approach and additional therapy is needed to kill the residual tumor cells. In this paper, we report a case in which a patient with a single very large liver cancer has been successfully treated by chemoembolization combined with radiotherapy. The results suggest that this is a very promising therapeutic approach for single large primary liver cancer.

Antibiotics, Antineoplastic↗

PubMedDate not supplied

Transient increased expression of VEGF and MMP-1 in a rat liver tumor model after hepatic arterial occlusion.

BACKGROUND/AIMS: This study investigates the influence of hepatic arterial occlusion (HAO) on blood perfusion of transplanted cancer in rat's liver, and the expression of vascular endothelial growth factor (VEGF) and matrix metalloproteinase-1 (MMP-1) and explores the mechanisms involved in transcatheter arterial embolization (TAE)-induced metastasis of liver cancer preliminarily. METHODOLOGY: Walker 256 carcinosarcoma was transplanted into rat's liver to create the liver cancer model. Hepatic arterial ligation (HAL) was used to block the hepatic arterial blood supply and simulate TAE. Rats bearing tumor were divided into three groups: control, laparotomy control, and HAL groups. Blood perfusion of tumor was analyzed by a Hoechst 33342 labeling assay. The level of serum VEGF was assayed by ELISA; and the expression of VEGF and MMP-1 mRNA was detected by in situ hybridization. RESULTS: Two days after HAL, the number of Hoechst 33342 labeled cells which represent the blood perfusion of the tumor directly and hypoxia of tumor indirectly in the HAL group decreased significantly compared with that in the control group (329.1+/-29.3 vs. 383.6+/-19.2, P<0.01). The level of serum VEGF in the HAL group increased significantly compared with that of the control group (92.5+/-43.9 pg/mL vs. 54.9+/-19.3 pg/mL, P<0.05). The expression of VEGF and MMP-1 mRNA in the tumor tissue of the HAL group increased significantly compared with that of the control and the laparotomy control groups (P<0.05). The blood perfusion data of the tumor, represented by number of Hoechst 33342 labeled cells, showed an inverse correlation with the expression of VEGF mRNA in tumor tissue (P<0.05). While 6 days after HAL, the blood perfusion of tumor in HAL group decreased and the expression of VEGF and MMP-1 increased only slightly, not significantly, compared with that in the control group. CONCLUSIONS: In conclusion, blockage of hepatic arterial blood supply results in transient decreased blood perfusion and increased expression of metastasis-associated genes VEGF and MMP-1 of transplanted liver cancer in rats. Decreased blood perfusion and hypoxia may be the major reason for up-regulated expression of VEGF. Better understanding of the mechanisms involved with TAE-induced metastasis may lead to the enhancement of the long-term effects of TAE for liver cancer.

Animals↗