Biomedical subjects

Yan-zhen Lin

Publications and source records attributed to Yan-zhen Lin.

15 recordsLinked to original sources

PubMed2006

[The relationship between frameshift mutations of transforming growth factor-beta type II receptor, insulin growth factor II receptor, bcl-2 associated X protein, E2F4 and microsatellite instability in gastric carcinoma].

OBJECTIVE: To determine the microsatellite instability in gastric carcinomas, examine the frameshift mutations of transforming growth factor-beta type II receptor (TGFbetaRII), insulin growth factor II receptor (IGFIIR), bcl-2 associated X protein (BAX) and E2F4, and investigate whether or how alterations of the TGFbetaRII, IGFIIR, BAX and E2F4 gene are associated with MSI in gastric cancer. METHODS: Formalin-fixed, paraffin-embedded gastrectomy specimens and matching normal tissues of 65 cases of gastric carcinomas were retrieved from shanghai Ruijin Hospital and Shanghai East Hospital. DNA was extracted from tissue sections using phenol chloral isoamyl alcohol. Sections with no more than 50% of tumor cell areas were isolated by microdissection. DNA was amplified by PCR-based single strand conformation polymorphism (SSCP) for microsatellite analysis and was sequenced directly. Frameshift mutations in the coding regions, repetitive mononucleotide tracts of (A)10 for TGFbetaRII, (G)8 for IGFIIR, (G)8 for BAX, and trinucleotide repeats of (AGC)13 for transcription factors E2F4 were detected using PCR. Tumors were classified as being microsatellite stable (MSS) or having a low frequency of MSI (MSI-L, one of markers different in the tumor) or a high frequency of MSI (MSI-H, two or more of markers different). RESULTS: Eleven cases (18.0%) showed MSI-L, 12 (19.7%) showed MSI-H and 38 (62.3%) cases showed MSS. The mutation rates of TGFbetaRII, IGFIIR, BAX and E2F4 gene were 19.7%, 4.9%, 6.6% and 16.4% respectively. Among the 12 MSI-H gastric cancers, there were 10 TGFbetaRII mutations, 3 IGFIIR mutations, 4 BAX mutations and 10 E2F4 gene mutations. The alterations in the repeats of the related genes presented polymorphisms. Associations of MSI-H status and mutations of the 4 genes were highly significant (P < 0.01, respectively). No repeat tracts mutations in TGFbetaRII, IGFIIR, BAX and E2F4 gene were found in MSS tumors. CONCLUSIONS: The repeat coding regions within TGFbetaRII, IGFIIR, BAX and E2F4 gene are the targets of microsatellite instability. Frameshift mutations of the 4 genes play an important role in the development and progression of gastric cancers with microsatellite instability.

Adult↗

PubMed2006

[Fusion expression of gastric cancer-related gene MPS-1 and preparation of rabbit antibody against GST-MPS-1].

AIM: To express the fusion protein GST-MPS-1 in E.coli and prepare rabbit antibody against GST-MPS-1. METHODS: MPS-1 cDNA was inserted into the vector of pGEX-5X. The recombinant was then transformed into E.coli BL21. After induction with the IPTG, the fusion protein GST-MPS-1 was expressed in E.coli. The purified fusion protein was then used to immunize the New Zealand rabbits to obtain the polyclonal antibody against GST-MPS-1. Specificity of the antibody was tested by Western blot and immunofluorescent staining. RESULTS: The cDNA sequence of MPS-1 in the recombinant was confirmed by restriction endonuclease digestion and sequence analysis. SDS-PAGE result showed that fusion protein was highly expressed in E.coli with a molecular weight of 36 kDa. The titer of the rabbit serum against GST-MPS-1 was as high as 1x10(5) in ELISA analysis. The polyclonal antibody were found to specifically bind to MPS-1 protein in Western blot and immunofluorescent staining. CONCLUSION: The preparation of the polyclonal antibody against MPS-1 lay a foundation for the further study of MPS-1 expression at protein levels and its function.

Blotting, Western↗

PubMed2006

[Clinical effect of intraoperative peritoneal hyperthermic chemotherapy for advanced gastric cancer].

OBJECTIVE: To investigate the clinical effect of intraoperative peritoneal hyperthermic chemotherapy (IPHC) for advanced gastric cancer (AGC). METHODS: A total of 118 AGC patients with serosal invasion were enrolled in this study from 1998 to 2001. Among these cases, 96 patients without macroscopic peritoneal metastases were selected for prophylactic study, including 42 cases with IPHC and 54 cases without IPHC as control. Other 22 patients with macroscopic peritoneal metastases were selected for therapeutic study, including 10 cases with IPHC and 12 without IPHC. Postoperative survival rate and peritoneal recurrence were compared. RESULTS: For prophylactic study, the 1, 2 and 4 years survival rates were 85.7%, 81.0% and 63.9% respectively in the patients with IPHC,significantly higher than 77.3%, 61.0% and 50.8% in the patients without IPHC. Cox ratio hazard model revealed that IPHC procedure was an independent prognostic factor. More patients in the control group suffered from peritoneal recurrence than those in IPHC group (34.7% vs 10.3%). For therapeutic study,the median survival period of the patients with IPHC was 10 months, higher than 5 months in the patients without IPHC. The overall 1, 2, 4 year survival rates were 76.9%, 69.2%, 55.2% respectively in all cases with IPHC, higher than 66.2%, 49.7%, 41.4% in the cases without IPHC. CONCLUSION: IPHC procedure can improve the prognosis of AGC patients with serosal invasion, reduce the risk for peritoneal recurrence, and is an independent prognostic factor.

Adult↗

PubMed2006

[Identification of biomarkers in the serum of the patients with poorly differentiated gastric cancer].

OBJECTIVE: To investigate the application of proteomics in the field of serology,and to screen the differential expression proteins related with poorly differentiated gastric carcinoma. METHODS: Two-dimensional electrophoresis (2-DE) was applied to segregate the total proteins in the serum form gastric cancer patients and health volunteers. After staining,the differential expression proteins were analyzed using PDQuest software,and identified using matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF-MS). RESULTS: Electrophoresis figures with high resolution and reproducibility were obtained. Six differential expression proteins were found only in the serum from gastric cancer patients, while four other proteins from healthy volunteers. CONCLUSIONS: Protein expression is differential in the serum from the gastric cancer patients and health volunteers. It is hopeful to find the biomarkers related with poorly differentiated gastric carcinoma using proteomics.

Adult↗

PubMed2006

[High-resolution analysis of chromosome 5 and identification of candidate genes in gastric cancer].

OBJECTIVE: To explore the relationship between loss of heterozygosity (LOH) of 5p with the histological phenotype in gastric cancer. METHODS: Eighty pairs of tumor and adjacent normal mucosa samples were collected and genomic DNA was extracted. Total of 17 polymorphic microsatellite markers for 5p were used for LOH analysis. A part of samples were fixed in 10% buffered formalin and stained with H&E. Histological type of gastric cancer was defined according to Lauren's classification. RESULTS: The average informative rate of all seventeen markers was 60.0%. The LOH at least in one locus was detected in 28 of the 80 (35.0%) cases. The highest LOH frequency occurring at D5S2849 (7.77 cM), with LOH frequency of 35.2% (19/54). The minimal LOH region was spanned from 6.67 to 9.41 cM (1.18 Mb, covering 2.7 cM), including D5S417, D5S2849, D5S1492 and D5S2088. In 28 with LOH, 24 (85.7%) cases were of intestinal type, and only 4 cases (14.3%) were of diffuse type. There is significant difference between LOH frequency in intestinal-type and diffuse-type gastric cancers (P < 0.01). Searching the NCBI database disclosed that this minimal deletion region at 5p15.33 covered 3 candidate genes, IRX1, IRX2, and CEI. CONCLUSION: The molecular events in 5p 15.33 may be related with the morphological differentiation and development of gastric cancer. Gastric cancer with LOH of 5p15.33 locus tends to develop in to intestinal type. The cluster of candidate genes in 5p15.33 may be closely implicated in carcinogenesis of intestinal type gastric carcinoma.

Adult↗

PubMed2006

[Gene expression profiling of diffuse-type gastric cancer by cDNA microarray].

OBJECTIVE: To identify cancer-related genes in diffuse-type gastric cancer and to explore its molecular mechanism by cDNA microarray analysis. METHODS: A total of 22 pairs of diffuse-type gastric cancer tissue and the corresponding normal mucosa were taken and freshly frozen. cDNA microarray with 14,592 genes/ESTs was used. Genes were considered to be up- or down-regulated when the fluorescent intensity ratio between tumor and normal mucosa was over 2-fold in over 50% of the samples (P < 0.05). Hierarchical clustering of regulated genes was performed as a measure to study expressional similarity. Validation of array results was carried out by real time quantitative PCR (QPCR). RESULTS: Compared with those of corresponding normal mucosa, there were a total of 153 genes/ESTs up-regulated and 204 down-regulated in diffuse-type gastric cancer. Hierarchical clustering demonstrated that the genes belonging to the same subgroup displayed similar function. Most of the overexpressed genes were those related to cell adhesion, cell motility, matrix reconstruction, cell proliferation and/or signal transduction; while genes related to defense response, toxicoid metabolism, DNA repairing, nuclear-cytoplasmic transport and/or anti-apoptosis made up the main list of the underexpressed genes. Seven genes showed higher expression in TNM (T I + T II) group than in (T III + T IV) group. QPCR confirmed the array analysis results. CONCLUSION: Gene expression profiling by cDNA microarray analysis provides not only molecular understanding of biological properties of cancer, but may also be helpful in discovering new diagnostic markers and therapeutic targets in gastric adenocarcinoma.

Adenocarcinoma↗

PubMed2005

[Inhibitory effect of dendritic cells pulsed with MAGE-3 peptide on transplanted murine gastric cancer in mice].

OBJECTIVE: To observe the inhibitory effect of MAGE-3 peptide pulsed DC on transplanted murine gastric cancer in 615 mice. METHODS: The CTL clones directed against MAGE-3 peptide were tested for the ability to lyse the gastric cancer cell line MFC which can express MAGE-3 antigen. In immunoprotection experiment, mice of the study group were immunized with MAGE-3 peptide pulsed DC (DC/MAGE-3) at the dosage of 1 x 10(6) on d0 and d7 by sc inoculation, mice of control groups were immunized with influenza virus peptide pulsed DC (DC/Nup) or unpulsed DC at the same dosage on days as the DC/MAGE-3 group. On d14, all the mice were challenged with sc injections of 5 x 10(5) MFC gastric cancer cells. In immunotherapy experiment, all the mice were sc injected 5 x 10(5) MFC gastric cancer cells on d0, and on d3, d10 mice of each groups were sc inoculated with DC/MAGE-3, DC/Nup or unpulsed DC at the dosage of 1 x 10(6) respectively. All mice were monitored closely with respect to tumor growth and survival times. RESULTS: The CTL clone induce by MAGE-3 peptide could lyse the MFC cells efficiently. Immunization of mice with DC pulsed with MAGE-3 generated partial protective immunity against MFC tumor, as well as significant inhibition of tumor growth in a 3-day tumor model. CONCLUSION: The tumor vaccine with DCs pulsed with MAGE-3 peptide possesses the ability to stimulate tumor specific CTL activity and to establish antitumor immunity when administered in vivo.

Animals↗

PubMed2005

[Study of hepatic injury during stop-flow chemotherapy].

OBJECTIVE: To observe the hepatic injury following stop- flow chemotherapy and investigate the potential mechanisms. METHODS: Twelve healthy hybrid female pigs were randomly divided into two groups as stop- flow group (SF) and stop- flow chemotherapy (SFC) group. The expression of IL- 8 and ICAM- 1 mRNA in hepatic biopsies was detected by RT- PCR, and the expression of NF- kappa B P65 subunit in nuclei was assessed by Western blot analysis. The levels of ALT and AST, and histopathologic alterations were examined to evaluate the hepatic function at different time before and after stop- flow procedure. RESULTS: The expression of NF- kappa B P65 subunit, IL- 8 and ICAM- 1mRNA increased at 30 min after stop- flow procedure, and gradually decreased at 3 h and 6 h after stop- flow procedure. The levels of ALT and AST decreased after reaching the peak at 24 h after stop- flow procedure, but removed one week after stop- flow procedure. Cytoplasmic microvascular steatosis developed with appreciable neutrophils infiltration after early stop- flow procedure without significant destroy occurred in the structure of hepatic lobule. No significant difference of various parameters above occurred between SF and SFC groups. CONCLUSION: The hepatic injury following stop- flow procedure was self-limited and reversible. There is no severe destroy of hepatic structure and disfunction during stop- flow chemotherapy.

Animals↗

PubMed2005

[Value of transabdominal ultrasonography in preoperative assessment of gastric carcinoma].

OBJECTIVE: To investigate the value of transabdominal ultrasonography (TAUS) in preoperative assessment of TNM stage and tumor angiogenesis for patients with gastric carcinoma. METHODS: Sixty- four patients with gastric carcinoma preoperatively underwent TAUS, in whom transabdominal color Doppler ultrasonography was used for measuring color Doppler vascularity index (CDVI) of each tumor in 37 cases and microvessel density (MVD) was evaluated by using immunohistochemical staining of surgical specimens with anti- CD34 antibody. RESULTS: The overall accuracy rate was 56.0% for T staging of gastric carcinoma (T (1) 2/3 cases, T (2) 28.6% , T (3) 73.1% , T (4) 50.0% , respectively) by TAUS. The diagnostic accuracy rate was 63.3% for lymph node status of gastric carcinoma. The diagnostic sensitivity and specificity for lymph node metastasis was 37.9% and 100% respectively. The overall accuracy for N staging of gastric carcinoma was 57.1% (N (0) 100% , N (1) 16.7% , N (2) 35.3% , respectively). The diagnostic sensitivity and specificity for determining distant metastases was 58.3% and 100% respectively. The CDVI of gastric carcinoma determined by color Doppler ultrasonography was significantly correlated to vascular invasion (P=0.0418), a linear correlation between CDVI and MVD was determined by logistic regression analysis (r=0.5628, P< 0.01). CONCLUSION: TAUS can be a routine diagnostic approach for preoperative gastric carcinoma patients.

Abdomen↗

PubMed2005

[Relationship between urokinase-type plasminogen activator expression and peritoneal metastatic potency in different gastric cancer cell lines].

OBJECTIVE: To compare the expression and activities of urokinase type plasminogen activator (uPA) among different gastric cancer cell lines and investigate their relations with peritoneal metastatic potency. METHODS: The uPA expression in 4 gastric cancer cell lines (AGS, SGC7901, MKN45, MKMN28) was detected using ELISA and Western blot methods. uPA activity was detected simultaneously using uPA activity kit. The gastric cancer cells were cultured with confluent mesothelial cells in 24-well plates or Boyden chambers for different times. The adhesive cells were counted directly under a microscope. The motility and invasion of gastric cancer cells were determined by MTT assay. RESULTS: Among four gastric cancer lines,the highest expression of uPA was found in SGC7901 and the highest uPA activity in MKN45, while the lowest expression and activity of uPA in AGS. Compared with the other three lines, MKN45 had stronger adhesion than MKMN28 (P< 0.05), SGC7901 (P< 0.05), and AGS (P< 0.01), but there were no significant differences in motility and invasion among MKN45, MKN28 and SGC7901. The adhesion,motility and invasion of AGS were weaker compared with those of the other three cell lines. CONCLUSION: The uPA expression and activity are significantly different among 4 gastric cancer cell lines, and positively correlated with their peritoneal metastatic potency.

Blotting, Western↗

PubMed2005

[COX- 2 expression in gastric cancer and its relationship with lymphangiogenesis and lymph node metastasis].

OBJECTIVE: To investigate the expression of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) in human gastric cancer, the relationship between their expression and the clinicopathological features,as well as the relationship between these two parameter expression and lymphangiogenesis and lymph node metastasis. METHODS: COX-2 and VEGF-C expressions were detected in 63 gastric cancer samples by immunostaining. Lymphangiogenesis was evaluated by immunostaining with the specific antibody LYVE-1. RESULTS: The expression rates of COX-2 and VEGF-C were 66.7% (42/63), 52.4% (33/63), respectively in 63 gastric cancer specimens. LYVE-1 was positive in 35 cases (35/63), which indicated lymphangiogenesis in the tumors. The expression of COX-2 was significantly correlated with the expression of VEGF-C, tumor lymphangiogenesis and lymphatic metastasis (P< 0.05), however not gender, tumor size, tumor location, Lauren classification and serosa invasion (P< 0.05). CONCLUSIONS: In gastric cancer, the expression of COX-2 is significantly associated with VEGF-C expression, lymphangiogenesis and lymphatic metastasis. COX-2 may up-regulate the expression of VEGF-C, which induces lymphangiogenesis and accordingly contributes to lymphatic metastasis.

Aged↗

PubMed2005

[Expression and clinical significance of cancer-related gene MPS-1 in gastric cancer].

OBJECTIVE: To investigate the expression of cancer-related gene MPS-1 in gastric cancer and to evaluate its significance in clinical diagnosis and therapy. METHODS: The mRNA expression of MPS-1 was determined by polymerase chain reaction after reverse transcription (RT-PCR) in cancer tissues and adjacent non-cancerous tissues from 42 cases with gastric cancer. The expression levels of MPS-1 in 6 gastric cancer cell lines (AGS, MKN-45, SGC 7901, KATO III, N-87 and SNU-1) were also determined by RT-PCR and Western blot. RESULTS: The MPS-1 mRNA was expressed in all tissues and cell lines. The mRNA expression level of MPS-1 in cancer tissues were 1.37+/- 0.87, significantly higher than 0.99+/- 0.67 in adjacent normal gastric mucous tissues (P< 0.01). The expression of MPS-1 was correlated with TNM stage (P< 0.05), but not with age, gender, tumor size and differentiation. The expression level of MPS-1 mRNA in the primary lesions was hig her in the patients with TNM stages III, IV than those with TNM stages I, II. Meanwhile, RT-PCR and Western blot showed the same results that MPS-1 expression was higher in the six gastric cancer cell lines as compared with that in the normal gastric cell line GES-1. CONCLUSION: The high expression of MPS-1 in gastric cancer indicates that MPS-1 might play an important role in gastric carcinogenesis,which may provide a new target in immunotherapy for gastric cancer.

Cell Cycle Proteins↗

PubMed2005

[Transcription factor Sp1 expression in gastric cancer and its prognostic value].

OBJECTIVE: To investigate the expression of transcription factor Sp1 in human gastric cancer tissues and normal gastric mucosa, and its prognostic significance. METHODS: By using immunohistochemistry, we studied the Sp1 expression patterns in 65 cases of gastric cancer with various clinico-pathologic characteristics, and 40 normal gastric mucosa specimens obtained from patients who underwent partial gastrectomy for benign gastric diseases. The significance of Sp1 expression on the survival of patients was evaluated. RESULTS: The expression rate of Sp1 in normal gastric mucosa was 12.5% (5/40). The positively stained glandular cells were mainly limited to those in the neck region. Cells at the basal portion of the gland were essentially negative. In sharp contrast, Sp1 expression rate in gastric cancer lesions was 53.8% (35/65). The medium survival time in patients who had a tumor with negative, weak and strong Sp1 expression was 1700, 1560 and 1026 days, respectively (P = 0.036). Sp1 protein expression was closely related to the depth of tumor invasion and TNM stage (P = 0.001, P = 0.026), but not related to the number of metastatic lymph nodes and Lauren's classification (P = 0.306, P = 0.667). CONCLUSION: Normal and malignant gastric tissues have unique Sp1 expression patterns. Sp1 might be served as an independent prognostic factor.

Adenocarcinoma↗

PubMed2003

[A preliminary study of endoscopic ultrasonography in the preoperative staging of early gastric carcinoma].

OBJECTIVE: To study the clinical value of endoscopic ultrasonography (EUS) in the preoperative staging of early gastric carcinoma. METHODS: EUS was performed in 149 gastric carcinoma patients proved by biopsy (including 33 patients with early gastric cancer), of which the results were compared with postoperative pathologic findings. RESULTS: The accuracy of EUS in determining the T stage of gastric carcinoma was 80.3% (T1 81.8%, T2 70.4%, T3 88.9%, T4 71.4%). The accuracy of EUS in differentiating early gastric carcinoma from advanced ones was 95.1%, and the accuracy of EUS in differentiating mucosal cancer from submucosal cancer was only 63.6%. The diagnostic accuracy of EUS for mucosal and submucosal cancer was 52.9% and 75%, with positive predictive value of 90% and 70.6%, respectively. The accuracy of invasion depth of EUS for the bulging and flat type of early gastric carcinoma was 100%, whereas the accuracy was only 58.6% for the depressed type. The accuracy of invasion depth of the differentiated and undifferentiated early cancer was 71.4%and 57.9%, without any significant difference (P > 0.05). The accuracy of invasion depth of EUS for early gastric carcinoma decreased as tumor size increased. The diagnostic accuracy of lymph node status of early gastric carcinoma by EUS was 90.9%, and the sensitivity and specificity of lymph node metastasis was 66.7% and 96.3%, respectively. CONCLUSION: The clinical value of endoscopic ultrasonography in the preoperative staging of early gastric carcinoma is relatively high.

Adenocarcinoma↗

PubMed2002

[In situ gene therapy for murine gastric carcinoma with UPRT/5-FU enzyme/prodrug system mediated by retrovirus].

BACKGROUND & OBJECTIVE: 5-Fluorouracil(5-FU), a widely used chemotherapeutic drug, has a limited overall effect in the treatment of human solid tumors due to resistance. This study was designed to investigate if antitumor activation of 5-FU could be enhanced by transfection of uracil phosphoribosyltransferase(UPRT) gene. METHODS: The UPRT gene encoding uracil phosphoribosyltransferase was amplified from Escherichia Coli K12 genome and subcloned into retrovirus expression vector pLXSN, Recombinant retrovirus was packaged and used further to infect murine gastric cancer cell line MFC. The sensitivity of MFC transfected with UPRT gene to 5-FU was determined by MTT method. In situ gene therapy was performed by regional repeated injections of concentrated and purified recombinant retrovirus carrying UPRT gene intratumorally and followed by administration of 5-FU intraperitoneally(i.p.). RESULTS: The 5-FU sensitivity in MFC transfected with the UPRT gene increased 17.26-fold compared to the control cells. In situ transfection of the UPRT gene mediated by retrovirus vector followed by the administration of 5-FU (10 mg/kg) significantly inhibited the tumor growth (P < 0.005) with an inhibition rate of 87.18% and prolonged the survival. CONCLUSION: Transfection of UPRT gene can render the murine gastric cancer cell line MFC be more sensitive to low concentration of 5-FU and significantly improve the antitumor effect of 5-FU both in vitro and in vivo.

Animals↗