Ethyl acetate extract of Pleione bulbocodioides(Franch.)Rolfe induces apoptosis of human leukemia K562 and HL-60 cells through intrinsic mi-tochondrial apoptosis pathway / 中国病理生理杂志

AIM:To investigate the effects of ethyl acetate(EtOAc)extract of Pleione bulbocodioides (Franch.)Rolfe on proliferation and apoptosis of human leukemia K 562 and HL-60 cells and the possible apoptosis path-way.METHODS:Human leukemia cell lines were treated with EtOAc extract of Pleione bulbocodioides at different con-centrations.XTT method was used to evaluate the viability of K 562 cells and HL-60 cells.The cell growth inhibition was calculated by Trypan blue exclusion test.The percentage of apoptotic cells was determined by flow cytometry,and 4,,6-dia-midino-2-phenylindole(DAPI)was used to observe morphological changes of the cells.The cell cycle was observed by pro-pidium iodide(PI)staining.The protein expression of Bcl-2, Bax, cleaved poly(ADP-ribose)polymerase(PARP), cleaved caspase-3,cytochrome C and apoptosis-inducing factor(AIF)wase determined by Western blot.RESULTS:The cell viability and proliferation were inhibited by EtOAc extract of Pleione bulbocodioides with IC50of(42.14 ±2.54)mg/L for HL-60 cells and(51.28 ±3.12)mg/L for K562 cells at 24 h.The results of Annexin V-FITC/PI and DAPI staining showed that EtOAc extract of Pleione bulbocodioides induced cell apoptosis in a dose-dependent manner.The apoptotic rate was increased compared with control group(P<0.05).The G2phase increased with typical cell apoptosis-induced mor-phological changes.The levels of pro-apoptotic proteins Bax,cleaved PARP and cleaved caspase-3 were increased, while Bcl-2 was down-regulated(P<0.05).Cytochrome C and AIF in cytosol,characteristic proteins of intrinsic mitochondrial apoptosis pathway,also increased with the concentration of EtOAc extract of Pleione bulbocodioides increasing(P<0.05). CONCLUSION:EtOAc extract of Pleione bulbocodioides significantly inhibits cell proliferation and induces cell apoptosis in human leukemia cell lines HL-60 and K562 through intrinsic mitochondrial apoptosis pathway.

Mutation screening of LKB1 gene in familial Peutz-Jeghers syndrome patients / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To screen for potential mutations of LKB1 gene in Chinese familial Peutz-Jeghers syndrome (PJS) patients and analyze their clinical manifestations.</p><p><b>METHODS</b>Eleven PJS families were collected and genomic DNA of peripheral blood was extracted. Typically mucosal pigmentation and hamartomatous polyps were present in all 11 probands. Mutation screening of the probands were carried out by PCR and direct sequencing. Two hundred and fifty healthy adults were enrolled as normal controls, for whom genomic DNA of peripheral blood was also extracted. PCR-denaturing high performance liquid chromatography was carried out to verify the mutation identified in the patients.</p><p><b>RESULTS</b>Nine germline mutations were identified in eight PJS patients, which included 7 point mutations, 1 deletion and 1 insertion. Among these, 4 were considered to be pathogenic, of which 2 were de novel, 4 were considered to be polymorphism, and 1 was uncertain.</p><p><b>CONCLUSION</b>LKB1 gene mutations with pathogenic effect are a common cause of familial PJS in Chinese patients. Most mutations are point mutations.</p>

Promoter hypermethylation and loss of heterozygosity of the APC gene in patients with familial adenomatous polyposis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the status of hypermethylation in the promoter 1A region of the adenomatus polyposis coli (APC) gene in 3 familial adenomatous polyposis (FAP) pedigrees and to screen large fragment deletions in the APC gene.</p><p><b>METHODS</b>DNA from tumor tissues and corresponding normal tissues of 5 FAP patients was modified by sodium bisulfite. Then the methylation status of the APC gene was analyzed by methylation specific-PCR (MSP) and DNA sequencing. Multiplex ligation-dependent probe amplification (MLPA) was used to screen aberrations involving large fragments from all the 15 exons and promoter region of APC gene.</p><p><b>RESULTS</b>No methylation was present in normal tissues. Hypermethylation was found in tumor tissues of one proband and her son. Loss of heterozygosity was observed in another patient from the same FAP family.</p><p><b>CONCLUSION</b>Aberrant methylation of the APC promoter region provides an important mechanism for impairing APC function and may occur early during colon neoplasia progression. Loss of heterozygosity may play a role in patients with classical polyposis.</p>

A novel APC gene germline mutation in a familial adenomatous polyposis pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the adenomatous polyposis coli (APC) gene germline mutation in the proband and her family members with familial adenomatous polyposis (FAP).</p><p><b>METHODS</b>The diagnosis of a patient with FAP was validated by colonoscopy, pathology and the family history. The systematic screening with multiplex ligation-dependent probe amplification (MLPA), denaturing high-performance liquid chromatography (DHPLC) and DNA sequencing were carried out to detect APC gene germline mutations.</p><p><b>RESULTS</b>A novel mutation c.1999 C >T (Q667X) of APC, which leads to premature termination of the protein, was identified in this family. This mutation manifested an aggressive form of FAP with early onset of colorectal adenocarcinoma and colonic adenoma.</p><p><b>CONCLUSION</b>The mutation of APC Q667X is the cause of clinical phenotype of this family with FAP, and the prophylactic colectomy for the affected family members should be considered.</p>

The analysis for identifying large DNA fragment aberrations of MSH2 and MLH1 genes from familial colorectal cancer in China / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the frequency of large fragment aberrations of MSH2 and MLH1 genes from Chinese colorectal cancer (CRC) patients with family history.</p><p><b>METHODS</b>Sixteen exons of MSH2, nineteen exons of MLH1 and seven DNA sequences from the other genes of the samples were screened and checked by multiplex ligation dependent probe amplification (MLPA). First, the methodology was confirmed by testing the positive and negative control samples. Then, 32 CRC or hereditary nonpolyposis colorectal cancer (HNPCC) patients with family history and 20 cases of sporadic CRC were applied to investigate for the large fragment aberrations of MSH2 and MLH1 genes.</p><p><b>RESULTS</b>The genomic DNA fragment deletions of all positive controls were identified and verified by MLPA. Three cases of 32 familial (hereditary) CRC/HNPCC were detected and identified to be the germline heterozygous deletions of MSH2 gene, of which exons 1-7 were deleted from patient No.3, exon 11 from No.25 and exons 2-6 from No.11. However, no genomic DNA fragment aberration of either MSH2 or MLH1 gene was uncovered from 20 sporadic CRC.</p><p><b>CONCLUSION</b>Large DNA fragment aberrations of MSH2 gene was a frequent cause of Chinese HNPCC and CRC patients with family history, and the identification of those aberrations should be included in the regular genetic analysis for CRC/HNPCC patients.</p>