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Mao-de Lai

Publications and source records attributed to Mao-de Lai.

30 records · Page 2Linked to original sources
PubMed2004

[Expression of beta-catenin in human colorectal adenoma and carcinoma].

OBJECTIVE: To investigate the expression of beta-catenin and its significance in colorectal neoplasms. METHODS: Tissue specimens of normal colorectal mucosa, mucosa adjacent to carcinoma, colorectal adenoma and adenocarcinoma were examined for beta-catenin with immunohistochemistry. RESULTS: Beta-catenin was mainly expressed in the cytomembrane of normal mucosa and mucosa adjacent to cancer (the positive rates were 94.6% and 86.5%, respectively) and also in the cytoplasm (the positive rates were 38.7% and 55.0%, respectively), while its expression was negative in the cell nucleus. In adenoma and adenocarcinoma, beta-catenin was mainly expressed in the cytoplasm (the positive rates were 85.1%,and 93.7%, respectively) and partially in the cell nucleus (the positive rates were 12.8% and 23.4%, respectively). Compared with normal mucosa and mucosa adjacent to cancer, the expression of beta- catenin in the cytomembrane of adenoma and adenocarcinoma was significantly lower (P<0.05), while its expression in the cytoplasm and cell nucleus of adenoma and adenocarcinoma was significantly higher (P<0.05). The positive rates of cytoplasm in highly-and moderately differentiated adenocarcinoma were significantly higher than that in poorly-differentiated adenocarcinoma (the positive rates were 100%, 95.5% and 68.8%, respectively). Beta-catenin expression rate in cytoplasm was correlated with Dukes'stages of adenocarcinoma, which was significantly lower in stage A than in stage B/C. CONCLUSION: The expression of beta-catenin is significantly correlated with differentiation and Dukes'stages of colorectal carcinoma and it can be used as an indicator for the prognosis of colorectal carcinoma.

Adenocarcinoma↗
PubMed2004

[Transforming growth factor beta receptor II mutations in RER positive colorectal cancers].

OBJECTIVE: To detect alterations of microsatellite loci [transforming growth factor beta receptor II (TGF-betaRII)(A)(10), TGF-betaRII(GT)(3), hMSH3(A)(8), hMSH6(C)(8), Bax(G)(8), IGFIIR(G)(8), IGFIIR(CT)(3)] and point mutations of TGF-betaRII (TGF-betaRII 452/454, TGF-betaRII 533). METHODS: PCR-SSLP, microdissection-PCR-SSLP, PCR-SSCP, clone sequencing and immunohistochemistry were used. RESULTS: The mutation rate of TGF-betaRII(A)(10) in RER+ (replication error positive) colorectal carcinomas was 33% (3/9). Similar mutations were also observed in adenomas with severe dysplasia. No mutations at other microsatellite loci were found. RER+ colorectal cancers mainly occurred in male patients at a young age and were more common in the colon than in the rectum (P < 0.05). CONCLUSIONS: RER+ colorectal cancers were found in young males and commonly located in the colon. A one third mutation rate in TGF-betaRII(A)(10) in these patients is lower than that observed in western populations, which may imply diverse pathways of carcinogenesis of RER+ colorectal carcinoma. TGF-betaRII(A)(10) mutation may play a role in the transforming process from an adenoma with severe dysplasia to a full blown carcinoma.

Adult↗
PubMed2003

[Severe acute respiratory syndrome].

OBJECTIVE: Severe acute respiratory syndrome(SARS), caused by SARS- associated coronavirus(SCV), is the first severe infectious disease in this century. SARS is pathologically characterized by interstitial exudative inflammation of lung with the formation of hyaline membrane in acute phase. Haemorrhagic inflammation exists in extrapulmonary organs. Clinical diagnosis is a dynamic process and includes the suspected case, probable case and definite case. Diagnostic standard of SARS will be revised with further understanding of the disease. Chinese term of SARS has been recommended in the paper.

Humans↗
PubMed2003

[Study of B2 gene structure and its expression in colorectal cancer].

OBJECTIVE: To get a complete cDNA sequence of B2 and evaluate the correlation on structure and expression between B2 and insulin like growth factor binding protein related protein 1 (IGFBP-rP1) in colorectal carcinomas, paired normal tissues, adenomas, tissues adjacent to the tumor, and colorectal carcinoma cell lines. METHODS: 5'RACE (rapid amplification of cDNA end) was applied to get the sequence of the 5' end of B2. Semi-quantitative RT-PCR and immunohistochemistry were used to detect the expression of B2 in colorectal cancer tissues and cell lines (SW480, SW1116, SW620, HCT8, CoLo205 and LoVo). RESULTS: A sequence of 1,125 bp was obtained by combining the sequence from 5'RACE product and the known sequence of B2. It shared 1,122/1,125 identities with IGFBP-rP1. At the level of mRNA, the expression of B2/IGFBP-rP1 was high in colorectal carcinomas, moderate in adenomas and tissues adjacent to tumor, low in normal tissues (P < 0.05). Five cell lines except SW480 showed no expression of B2/IGFBP-rP1. A significant difference was obtained in the immunoreactivity of B2/IGFBP-rP1 between normal tissue and cancer (P < 0.05). In 28.9% (22/76) samples, cancer cells locating at the invasive front of cancer nest had a stronger staining of B2/IGFBP-rP1 than those surrounding the lumen. These samples had also an increased frequency of lymph node metastases, increased depth of invasion and a stronger staining of B2/IGFBP-rP1 than in other samples (P < 0.05). CONCLUSIONS: B2 is the same gene as IGFBP-rP1. Overexpression of B2/IGFBP-rP1 may play an important role in the initiation and promotion of colorectal cancer. Its overexpression in invading tumor cells may be linking with an increased potential of invasion.

Adenocarcinoma↗
PubMed2003

[Screening the differentially methylated DNA sequences of colorectal cancer by methylated CpG islands amplification coupled with representational difference analysis].

OBJECTIVE: To screen the differentially methylated DNA sequences between mucosa adjacent to colorectal cancer (MACC) and normal colonic mucosa. METHODS: The methylated DNA sequences were enriched by methylation CpG islands amplification (MCA), and the differentially methylated DNA sequences between MACC and normal colonic mucosa were isolated by representational difference analysis (RDA). Similarities between the separated fragments and the human genomic DNA were analyzed with BLAST program system in GenBank. With the separated fragment 1A12 as probe, dot blot was used to study its distribution between RDA products (No. 1-4 rounds), MACC (tester) and normal colonic mucosa(driver). RESULTS: Twenty-five differentially methylated DNA sequences were obtained. Preliminary studies indicated that 1A01 fragment was concerned with two different genes (LOC256866 and CECR7), it was located in the first exon of CECR7. 1A12 fragment was located in 5 flanking region of GR6 gene. By dot blot with 1A12 probe, hybridized signals were detected in MCA product of MACC and RDA products of No. 1-4 rounds, respectively. No signal was detected in MCA product of normal colonic mucosa. CONCLUSION: The differentially methylated DNA sequences can be isolated effectively between two different tissues with MCA coupled with RDA. Different methylated DNA fragments exist between MACC and normal colonic mucosa and these fragments may be concerned with colorectal cancer.

Adult↗
PubMed2002

Increased sensitivity of colorectal cancer cell lines with microsatellite instability to 5-fluorouracil in vitro.

OBJECTIVE: To study the relationship between sensitivity to 5-FU and the status of a panel of microsatellite loci in three human colon cancer cell lines. METHODS: Cell viability in several concentrations of 5-FU was assessed by the MTT test. Expression of hMSH2 and hMLH1 in LoVo, SW480 and SW1116 cells were analyzed by immunocytochemical staining.Ten mononucleotide and dinucleotide microsatellite loci were analyzed by the PCR-SSLP-silver staining method. RESULTS: By MTT assay, it showed that LoVo cells were more sensitive than SW480 and SW1116 cells (0.8 micromol/L,2.2 micromol/L and 1.9 micromol/L, respectively, P < 0.05). By immunocytochemical staining, hMSH2 was expressed in SW480 and SW1116 cells but not in LoVo cells, while hMLH1 was positive in all three cell lines. The PCR-SSLP-silver staining of 10 microsatellite loci revealed that LoVo cells had a different pattern of electrophoretic bands compared with SW480 and SW1116 cells, manifesting both additions and band-shifts. CONCLUSION: Together with hMSH2 and hMLH1, the status of a panel of microsatellite loci may be used as convenient predictors for drug-optimization or prognosis-assessment in colorectal cancer patients before chemotherapy.

Adaptor Proteins, Signal Transducing↗