Relationship between p53 gene and chromosome 13q14 variations and prognosis in primary intestinal lymphoma / 中国当代儿科杂志

<p><b>OBJECTIVE</b>Some research has shown that primary intestinal lymphoma with the same immunophenotype has different prognosis. It suggests that the prognosis of this disease is not determined by a single factor but may be related to genetic or chromosomal variations. The p53 gene is an important tumor suppressor gene, and 13q14 deletion is a common chromosomal abnormality of lymphocyte proliferation diseases. This study aimed to explore the role of the p53 gene and chromosome 13q14 variations in the assessment of prognosis in primary intestinal lymphoma.</p><p><b>METHODS</b>p53 gene and chromosome 13q14 expression in paraffin sections of 30 cases of primary intestinal lymphoma and 10 cases of lymph node reactive hyperplasia were ascertained using an improved FISH technique.</p><p><b>RESULTS</b>p53 gene deletion was found in 22.7% of patients with primary intestinal lymphoma at stage I-II and in 75.0% of patients at stage III-IV (x2=6.903, p<0.01). The 30 patients with primary intestinal lymphoma were pathologically classified into-mucosa-associated lymphoid tissue (MALT) (n=14) and non-MALT types (n=16). The MALT lymphoma group had significantly lower incidence of p53 gene deletion (14.3% vs 56.3%; x2=5.662, p<0.05). Average survival time in patients with p53 gene deletion was 13.41 months, being shorter than the patients with normal p53 gene (36.1 months) (t=2.637, p<0.05). 13q14 deletion was found in 40.0% of patients with primary intestinal lymphoma, but none of patients with lymph node reactive hyperplasia showed 13q14 deletion. 13q14 deletion was not significantly related to the pathological type and the clinical stage of primary intestinal lymphoma as well as the survival time. There was no significant correlation between p53 gene and 13q14 deletions.</p><p><b>CONCLUSIONS</b>There was a high incidence of p53 gene deletion in patients with non-MALT lymphoma or at stage III-IV. p53 gene deletion is related to a high tumor malignant degree and a poor prognosis, while-chromosome 13q14 variation is not associated with the prognosis in patients with primary intestinal lymphoma.</p>

Biological implication of PTEN gene expression in human gastric cancer and related molecular mechanisms / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the role of PTEN gene involved in the biological behavior of human gastric carcinoma cells and underlying molecular mechanisms.</p><p><b>METHODS</b>Gastric carcinoma cell line, SGC7901, was transfected with plasmid PBP-PTEN and stable high PTEN expression clones were selected by Western blot and cell immunohistochemistry screening. Cell proliferation rate and apoptosis index of transfected cells were investigated by growth curve analysis, colony-formation assay and flow cytometry (FCM). Expressions of vascular endothelial growth factor (VEGF), matrix metalloprotease-2 (MMP-2) and MMP-9 proteins in cell culture supernatant and cytoplasm were determined by ELISA, gelatin zymogram, Western blot and cell immunohistochemistry.</p><p><b>RESULTS</b>Stable clone with high level expression of PTEN was successfully established (PTEN-SGC7901). Cell doubling time of PTEN-SGC7901 was longer than that of the control cells (P < 0.05). The size and colony-forming efficiency of PTEN-SGC7901 cells deceased compared with those of the control. The relative colony-inhibition efficiency of PTEN-SGC7901 to SGC7901 (naïve untransfected) and PBP-SGC7901 (control vector transfected) cells were 69.8% and 64.8%, respectively. PTEN-SGC7901 clone had more cells at G1 phase (P < 0.05) compared with that of the control. However, the apoptosis index did not show significant differences among the three groups (P > 0.05). There were significantly less VEGF and MMP-9 protein expressions in the PTEN-SGC7901 culture supernatant and cytoplasm (P < 0.05). In contrast, the MMP-2 expression among three cell groups had no significant difference (P > 0.05).</p><p><b>CONCLUSIONS</b>PTEN expression suppresses the growth and proliferation of gastric carcinoma cell SGC7901, possibly through an inhibition of the expressions of VEGF and MMP-9.</p>

Expressions of TGIF, MMP9 and VEGF proteins and their clinicopathological relationship in gastric cancer / 中南大学学报(医学版)

OBJECTIVE@#To detect the expressions of TG-interacting factor (TGIF), matrix metalloproteinase 9 (MMP9) and vascular endothelial growth factor (VEGF) proteins, and to analyze their clinicopathological relationship in gastric cancer.@*METHODS@#Vascular invasion and remote metastasis were examined in nude mice inoculated with SGC-7901 cells, vector control cells or TGIF transfected cells via serial sections, and sequentially the expressions of MMP2, MMP9 and VEGF proteins in tumor tissues from nude mice were detected by immunohistochemical staining. At the same time, TGIF, MMP9 and VEGF proteins were examined in 76 patients with gastric carcinoma, and the relationships between the expressions of the three proteins and clinicopathological features were analyzed.@*RESULTS@#Metastasis was not observed in nude mice inoculated with any cells. There were cancerous embolisms in nude mice tumor tissue inoculated with SGC-7901 cells and vector control cells, but not in TGIF transfected cells. The expressions of MMP9 and VEGF proteins were higher in the tumor tissues originated from SGC-7901 cells and vector control cells than that from TGIF transfected cells. The expression of MMP2 had no distinct difference among the tumor tissues originated from the three cells. The positive rate of TGIF protein in gastric carcinoma was 46.1% (35/76), obviously lower than that in surgical marginal mucosa (78.1%) (P < 0.05). Low expression of TGIF protein correlated significantly with the metastasis of lymph node. The positive rates of MMP9 and VEGF proteins in gastric carcinoma were 59.2% and 56.6%, respectively, obviously higher than that in surgical marginal mucosa (31.3%) (P < 0.05). High expressions of both MMP9 and VEGF also correlated significantly with the metastasis of lymph node. The expression level of VEGF protein was also associated with the invasion of gastric carcinoma (P < 0.05). The expression of TGIF protein reversely correlated with that of MMP9 and VEGF proteins (P < 0.05).@*CONCLUSION@#TGIF may inhibit the invasion and metastasis of gastric carcinoma via the downregulation of MMP9 and VEGF proteins.

Growth suppression of colon cancer cells in vitro by DPC4 gene expression and its mechanism / 中华病理学杂志

<p><b>OBJECTIVE</b>To study the effect of DPC4 gene expression on the growth of colon cancer cells and its mechanism.</p><p><b>METHODS</b>Expression plasmid pcDNA3.1-DPC4 was constructed and transfected into the colon cancer cell line SW620 by use of lipofectamine gene transfer technique. DPC4 protein expression was detected by Western blot and immunocytochemistry. The effect of DPC4 gene on the growth of SW620 cells was monitored by population doubling time (PDT) and cloning efficiency. The influence of DPC4 expression on p21WAF1 transcription was investigated by RT-PCR to detect p21WAF1 mRNA.</p><p><b>RESULTS</b>Successful expression of DPC4 protein was detected in the transfected SW620 cells. Compared with the control cells, PDT (74 h) of the DPC4 expressing cells was prolonged and the cloning efficiency (21%) decreased. In addition, the mRNA level of p21(WAF1) in DPC4 transfected cells was increased.</p><p><b>CONCLUSIONS</b>Overexpression of DPC4 gene inhibits the growth of colon cancer in vitro, and induction of p21(WAF1) expression may be an important functional aspect of DPC4.</p>