Relationship between chromosome behaviour and stability of human-mouse and human-(human-mouse)hvbridomas

Chromosomes in human-mouse and human-(human-mouse)hybridomas wereanalysed by G-banding methods.It was found that most human chromosomes,exceptNo.13 and X,Y,were retained.The frequencies of chromosomes No.1,3,4,5,6,17,19,21 and 22 were higher than those of other chromosomes in each hybridoma clone.The myeloma cell lines X63-Ag8.653 and SHM-D33 were also analysed.The morphologyof marker chromosomes was apparently different between hybridomas.There were 7 kindsof marker chromosomes in human-mouse hybridomas and 16 kinds of markerchromosomes in human-(human-mouse)hybridomas.Clones that retained humanchromosome No.1 were more stable and clones that did not retain human chromosomeNo.14 were still capable of secreting human immunoglobulin.Clones that retained humanchromosome No.2 did not secret human k light chain McAb while clones that retainedhuman chromosomes No.2 and No.22 only secreted λ light chain.

Molecular Profile of Human Serine Palmitoyltransferase-1 Proximate of Chromosome 9 Disease Susceptibility Gene Cluster in Inflammatory Cancer Cell Lines

Background: Over 1100 genes have been annotated for human chromosome 9, including disease genes implicated in inflammation, atherosclerosis, cancer and neurodegeneration. The serine palmitoyltransferase-1, SPTLC1, gene is at the 9q22.2 cytogenetic band, a high G+C content region with common genetic alterations sufficient to modify cellular behavior. The sequence is highly conserved among diverse species from bacteria to humans, including a recently discovered 126 nucleotide alternate open reading frame, AltORF. The protein encoded by the reading frames has domains of biological interest and considerable overlapping molecular functions associated with cellular behavior and cancer progression. Methods: Here we examined molecular features of SPTLC1 in a group of inflammation associated cancer cell lines SKN-SH, MDA-PCa, Glioma LN18, PC3 and 647V. Subcellular localization of SPTLC1 was assessed by immunofluorescence microscopy and recombinant green fluorescent protein expression. In addition, PCR, DNA sequencing and bioinformatics analysis were used for molecular profiling of the SPTLC1 genomic and reverse transcribed cDNA fragments. Results: SPTLC1 is detected in all cell lines examined, with intense peri-nuclear staining, consistent with localization in the cytoplasm. Genomic DNA sample, but not the cD NA of SKN cells could be amplified with an AltORF primer set. The PC3 and MDA-PCa cancer cell lines which are both of prostate origin, show differences in SPTLC1 PCR amplification. Similar levels of SPTLC1 AltORF transcripts were detected by quantitative RT-PCR in all cell lines, except the PC3 cell line with low transcript level whose cDNA did not generate nucleotide base sequence information. Conclusions: This is the first reported transcriptional expression of the SPTLC1 AltORF for the inflammation associated human cancer cell lines. Interestingly, it is proximate of oncogenic cancer susceptibility genes and distal of tumor suppressor genes, the high content of short nucleotide repeats in the SPTLC1 AltORF sequence suggesting the region may be genetically unstable. This nominal functional genomics report on the human SPTLC1 AltORF will contribute to compiling a more detailed SPTLC1 gene ontology and is expected to help shed more insight into unique molecular attributes of SPTLC1 in the context of cancer cell behavior, malignant progression and the design of treatment for inflammation associated cancers.

Cloning and characterization of a novel gene (C17orf25) from the deletion region on chromosome 17p13.3 in hepatocelular carcinoma

Using a combination of hybridization of PAC to a cDNA library and RACE technique, we isolated a novel cDNA, designated as C17orf25 (Chromosome 17 open rea(ling frame 25, previously named it HC71A), from the deletion region on chromosome 17p13.3. The cDNA encodes a protein of 313 amino acids with a calculated molecular mass of 34.8 kDa. C17orf25 is divided into 10 exons and 9 introns, spanning 23 kb of genomic DNA. Northern blot analysis showed that the mRNA expression of C17orf25 was decreased in hepatocellular carcinoma samples as compared to adjacent noncancerous liver tissues from the same patients. The transfection of C17or25 into the hepatocellular carcinoma cell SMMC7721 and overexpression could inhibit the cell growth. The above results indicate that C17orf25 is a novel human gene, and the cloning and preliminary characterization of C17orf25 is a prerequisite for further functional analysis of this novel gene in human hepatocellular carcinoma.

Exploring Codon Usage Patterns of Alternatively Spliced Genes in Human Chromosome 1

In this study, 414 whole protein-coding sequences (238 004 codons) of alternatively spliced genes of human chromosome 1 have been employed to explore the patterns of codon usage bias among genes. Overall codon usage data analysis indicates that G- and C-ending codons are predominant in the genes. The base usage in all three codon positions suggests a selection-mutation balance. Multivariate statistical analysis reveals that the codon usage variation has a strong positive correlation with the expressivities of the genes (r=0.5790, P<0.0001). All 27 codons identified as optimal are G- and C-ending codons. Correlation analysis shows a strong negative correlation between the gene length and codon adaptation index value (r=0.2252, P<0.0001), and a significantly positive correlation between the gene length and Nc values (r=0.1876, P<0.0001). These results suggest that the comparatively shorter genes in the genes have higher codon usage bias to maximize translational efficiency, and selection may also contribute to the reduction of highly expressed proteins.

High frequency loss of heterozygosity on the long arms of chromosomes 13 and 14 in nasopharyngeal carcinoma in Southern China

OBJECTIVE: To investigate the loss of heterozygosity (LOH) on chromosomal arms 13q and 14q in nasopharyngeal carcinoma (NPC) using 21 microsatellite polymorphic markers and to study whether there is a correlation between LOH and clinicopathologic parameters and/or Epstein-Barr virus (EBV) infection in NPC. METHODS: Sixty cases of NPC were studied using polymerase chain reaction based microsatellite analysis with genescan and genotyping techniques. RESULTS: LOH was detected on 13q in 78% of NPC tumors, high frequency LOH loci (more than 30%) clustered to 13q12.3-q14.3 and 13q32. On chromosome 14q, LOH was detected in 80% of NPC tumors; high frequency LOH loci clustered to 14q11-q13, 14q21-q24 and 14q32. High frequency LOH at 13q31-q32 correlated with a lower level of EBV infection; LOH on chromosome 14q was closely associated with poor differentiation of NPC tumor cells. CONCLUSION: Our results suggest that in NPC, LOH on chromosome 13q and 14q are common genetic events, and putative tumor suppressor genes (TSG) residing in these regions may be involved in tumorigenesis.

cDNA cloning, chromosome mapping and expression characterization of human geranylgeranyl pyrophosphate synthase

Geranylgeranyl pyrophosphate (GGPP) mainly participates in post-translational modification for various proteins including Rho/Rac, Rap and Rab families, as well as in regulation for cell apoptosis. Geranylgeranyl pyrophosphate synthase (GGPPS), which catalyzes the condensation reaction between farnesyl diphosphate and isopentenyl diphosphate, is the key enzyme for synthesizing GGPP. We report the isolation of a gene transcript showing high homology with Drosophila GGPPS cDNA. The transcript is 1 466 bp in length and contains an intact open reading frame (ORF) ranging from nt 239 to 1 138. This ORF encodes a deduced protein of 300 residues with calculated molecular weight of 35 ku. The deduced protein shows 57.5% identity and 75% similarity with Drosophila GGPPS, and contains five characteristic domains of prenyltransferases. Northern hybridization revealed that human GGPPS was expressed highest in heart, and moderately in spleen, testis, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. No obvious bands were detected in other examined tissues. The GGPPS gene was located on human chromosome 1q43 by Radiation Hybrid mapping method. It was proved that there was a putative predisposing gene for prostate cancer in this region, and that analogs of GGPP can inhibit the geranylgeranylation of p21 rap protein in PC-3 prostate cancer cell lines. These facts suggest that GGPPS may be one of the candidate genes for prostate cancer.

Chromosome 14q may harbor multiple tumor suppressor genes in primary glioblastoma multiforme

OBJECTIVE: To evaluate whether deletion of chromosome 14q is involved in the carcinogenesis of primary glioblastoma multiforme and to identify possibly common deletion regions. METHJODS: Fourteen fluorescent dye-labeled polymorphic markers were used and polymerase chain reaction-based microsatellite analysis was employed to investigate loss of heterozygosity (LOH) on chromosome 14q in 20 primary glioblastoma multiforme (GBM). RESULTS: Ten of twenty (50%) GBM displayed LOH at one or more of the markers on chromosome 14q. Five tumors showed either LOH or non-informative on all markers tested. The most frequent LOH was observed at locus D14S65 (57.1%) on 14q32.1, and in the chromosomal region spanning from D14S63 (47.1%) to D14S74 (46.7%) on 14q23-31. None of the informative loci exhibited microsatellite instability. CONCLUSIONS: Allelic deletion on chromosome 14q plays an important role in the pathogenesis of GBM. Chromosomal regions at locus D14S65 on 14q32.1 and spanning from D14S63 to D14S74 on 14q23-31 may harbor multiple tumor suppressor genes associated with GBM.

The predictive value of chromosome 8p deletion for metastasis of hepatocellular carcinoma:a summary of works in 10 years

Hepatocellular carcinoma(HCC)represents an extremely poor prognostic cancer,which is mainly due to the high frequency of metastasis/recurrence after surgical operation.Exploring the molecular mechanisms involved in HCC metastasis could be helpful in the pre-diction and early diagnosis of HCC recurrence and could also provide new therapeutic targets for HCC metastasis.In the recent decade,we analyzed the genomic aberrations of the clinical specimens,as well as the metastatic models and cell lines of human HCC to identify the genetic mar-kers related to HCC metastasis and to verify their clinical values in the prediction and control of metastasis of HCC.Using the comparative genomic hybridization(CGH)technique,we compared the differences of chromosomal aberrations between primary HCC tumors and their matched metastatic lesions,and found that chromosome 8p deletions might contribute to HCC metastasis.This novel finding was further confirmed by comparison between nude mice models of HCC with different meta-static potentials.By the more sensitive genome-wide microsatellite analysis,8p deletion was defined to 8p23.3 and 8p11.2,which are two likely regions harboring meta-stasis-related genes of HCC.Using‘8p-specific’microar-rays,two novel metastatic suppressors(HTPAP and MRSA)were identified,and were proven to suppress in vitro invasion and in vivo metastasis of HCC.Clinical studies indicate that 8p deletion detected in HCC or cir-culating plasma DNA of patients is a useful predictor for metastatic recurrence and prognosis,even for patients with early stage HCC.These novel findings are regarded as important advances in the study of the molecular mechanisms of HCC metastasis,which provide not only a holistic view on the molecular cytogenetic bases of HCC metastasis,but also candidate regions for further study to identify metastatic suppressor genes.

Familial Wolff-Parkinson-White syndrome is linked to the loci on chromosome 7q3

OBJECTIVE: Wolff-Parkinson-White syndrome (WPW) is considered to be an autosomal dominant hereditary disease, but the gene is not identified. The objective of this study was to localize the genetic loci of Wolff-Parkinson-White syndrome. METHODS: Linkage analysis between the disease of Wolff-Parkinson-White syndrome and 3 STR (short tandem repeats) markers on 7q3 (D7S505, D7S688, and D7S483) was tested in 3 kindreds of the Wolff-Parkinson-White syndrome (101 numbers in total) by genotyping. RESULTS: Wolff-Parkinson-White syndrome was linked to the loci above. The maximum two-point Lod score detected at D7S505 was 6.4 at a recombination fraction (theta) of 0.1; the Lod score of D7S688, D7S483 was 5.3 vs 2.5. CONCLUSION: The gene of Wolff-Parkinson-White syndrome is located at 7q3.

Linkage analysis of a region on chromosome 2 with essential hypertension in Chinese families

OBJECTIVE: To verify the linkage of the candidate regions identified in a previous study (markers D2S168, D2S151, D2S142 on chromosome 2) with hypertension in Chinese families. METHODS: A genetic linkage study focused on chromosome 2 was performed on 240 Chinese families containing 856 patients with essential hypertension. A total of 1080 individuals were genotyped using 9 highly polymorphic microsatellite markers around the candidate regions on chromosome 2 with an average spacing of 5 cM. Non-parametric linkage (NPL), parametric linkage analysis and transmission-disequilibrium test (TDT) with the GENEHUNTER software were used to assess evidence for linkage. RESULTS: Linkage of a region on chromosome 2 around D2S151 and D2S142 with hypertension was confirmed by different statistical methods (NPL, LOD score and TDT). However, the linkage of D2S168 could not be replicated in this extension study. CONCLUSIONS: The data suggest that a region on chromosome 2 at or near the loci of D2S142 and D2S151 may harbor genes responsible for the development of essential hypertension in Chinese.

Cloning, tissue expression pattern, and cnromosome localization of human protein kinase By gene

Protein kinase B (PKB) is a member of the second messenger-regulated subfamily of protein kinases, and plays a key role in cell-cycle regulation, glucose uptake and promotion of cell differentiation. Evidence shows that PKB undergoes activation in some human tumors and is involved in Ras pathway, which implies that PKB can trigger a pathway to induce oncogenic transformation. A nucleotide sequence of mouse Pkbywas used as a probe to screen homolog in a human liver cDNA library. A fragment of 1998 bp containing a 1440 bp ORF encoding 479 amino acid residues was obtained. Then the 3’-terminal of this fragment was extended to 2788 bp by ’electronic walking’ screening, and the extended fragment was confirmed by PCR amplification. The protein deduced by the gene had a high identity of 83% and 78% to the human PKBα and β, respectively, and was designated as human PKBγ. Northern hybridization detected two equally expressed transcripts of 8.5 and 6.5 kb in length in all 16 human tissues tested, with the

乳腺癌17号染色体多体对HER2检测的影响及其临床病理学意义

目的:探讨乳腺癌17号染色体多体对人类表皮生长因子受体2(epidermal growth factor receptor 2,HER2)检测结果的影响及其临床病理学意义。方法:采用荧光原位杂交(fluorescencein situhybridization,FISH)双色法检测71例原发性浸润性乳腺癌中HER2基因和17号染色体拷贝数目情况。采用HER2绝对拷贝数标准和HER2/chromosome 17比值标准,判定HER2的FISH检测结果;基于FISH检测结果,结合免疫组织化学法(immunohistochemistry,IHC)检测的HER2蛋白表达情况及相关临床病理参数进行分组对比分析。结果:无论按照HER2绝对拷贝数标准(14/71,19.7%)或HER2/chromosome17比值标准(2/71,2.8%),所有FISH检测结果示HER2基因扩展可疑的病例都为17号染色体多体;与HER2基因扩增阴性者相比,单纯17号染色体多体组在肿瘤分级、淋巴结转移以及激素受体表达上差异无统计学意义(P均>0.05);而与HER2基因扩增阳性组相比,单纯17号染色体多体组表现出更低的肿瘤分级(50.0%vs81.5%,P=0.025)、更高的淋巴结阴性率(55.6%vs25.9%,P=0.045)以及更高的雌激素受体(estrogen receptor,ER)阳性率(83.3%vs41.7%,P=0.005)和孕激素受体(progestogen receptor,PR)阳性率(87.5%vs44.4%,P=0.003)。结论:相比于HER2基因扩增组,单纯17号染色体多体组更倾向于HER2基因扩增阴性;17号染色体多体会影响HER2检测结果,是FISH检测中导致可疑结果产生的主要原因。

成人Silver-Russell综合征1例并文献复习

Silver－Russell综合征是罕见遗传性疾病，临床表现异质性大，故诊断困难。1例成人女性Silver－Russell 综合征患者，以身材矮小、肢体不对称伴右侧肥胖、第五手指弯斜和髋关节脱位为主要临床表现，染色体检测提示（46，XX）。患者10岁时曾行右下肢延长手术。入院时肢体不对称伴右侧肥胖影响肢体功能，入院后行右侧臀部和大腿整形术，术后运动功能好转。

低形态学评分卵裂期胚胎的X、Y及18号染色体分析

目的:分析低形态学评分的D3卵裂期胚胎X、Y及18号染色体的非整倍体情况。方法:收集体外受精-胚胎移植术后剩余的废弃胚胎,胚胎固定后采用荧光原位杂交技术检测细胞核内的X、Y及18号染色体。结果:共收集废弃胚胎60个,其中正常胚胎29个,18号染色体异常胚胎12个,X/Y染色体异常胚胎8个,18、X/Y染色体均异常胚胎11个。观测到荧光信号的细胞核有233个,其中正常细胞核115个(49.4%),异常细胞核118个(50.6%)。18号染色体非整倍体率40.8%,X/Y染色体非整倍体率33.5%,差异无统计学意义(χ2=2.65,P>0.05)。18号染色体三体发生率(21.9%)与X/Y染色体三体发生率(12.0%)差异有统计学意义(χ2=11.58,P<0.01)。结论:D3形态评分低的胚胎有相当大的比例存在染色体异常,通用的胚胎形态学评分系统能够在一定程度上反映胚胎的染色体情况。

F11R基因多态性与精神分裂症的关系

目的 :探讨 1号染色体上 F11R基因多态性与精神分裂症的关系。方法 :采用聚合酶链式反应 -限制性内切酶片段长度多态性 (PCR- RFL P)的方法对 12 8例精神分裂症患者、 114例健康对照 1号染色体 F11R基因上的一个 SNP进行基因型检测 ,应用 SPSS统计学软件数据处理 ,并进行统计学分析。结果 :等位基因 A和 G的频数分布在病例组和对照组中无统计学意义 (χ2 =0 .4 98,P>0 .0 5 ) ;AA和 AG两种基因型频数分布在病例组和对照组中也无统计学意义 (χ2 =0 .5 33,P>0 .0 5 )。结论 :1号染色体上的 F11R基因可能不是精神分裂症的易感基因。

散发性结直肠癌1号染色体短臂遗传位点杂合缺失

目的:抑癌基因的杂合缺失(loss of heterozygosity,LOH)被认为是结直肠癌形成的关键步骤之一。本实验研究了结直肠癌1号染色体短臂杂合的缺失情况,并探讨其临床意义。方法:选取11个微卫星DNA标记与83例结直肠癌病例的肿瘤和正常组织进行PCR。PCR产物在ABIPrism377自动荧光测序仪上进行电泳,以GeneScan3.1和Genotyper2.1软件进行遗传位点扫描以及杂合缺失分析。结果:1号染色体短臂的平均杂合缺失率为18.00%,D1S468(1p36.33-36.31)位点的杂合缺失率最高,达36.54%。D1S2726位点的杂合缺失现象主要存在于直肠癌,缺失率为28.57%(6/21),而结肠癌的缺失率为0.00%(0/33),二者差异具统计学意义(P=0.002)。结论:在1号染色体短臂上可能存在与结直肠癌发生相关的抑癌基因,位于1p36.33-36.31这个区域。

晚裂胚胎性染色体及18号染色体非整倍体分析

目的:分析晚裂胚胎性染色体及18号染色体数目异常情况。方法:应用荧光原位杂交技术检测晚裂胚胎X、Y及18号染色体的非整倍体情况,并与低评分的双原核(2PN)胚胎进行比较。结果:共收集85个胚胎,其中晚裂胚胎45个(不考虑形态学评分),成功固定269个核;低形态学评分的2PN胚胎40个,成功固定243个核,用CEPX/Y、CEP18染色体探针对85个胚胎共512个核进行荧光原位杂交。晚裂胚胎组的染色体数目异常率为45.7%,其中性染色体异常率为34.5%,18号染色体异常率为38%;2PN胚胎组的染色体异常率为48.5%,其中性染色体异常率为32%,18号染色体异常率为39%。2组性染色体和18号染色体的异常率差异均无统计学意义。结论:晚裂胚胎性染色体及18号染色体数目有较高的异常发生率,与低形态学评分的2PN胚胎一样,均不适合宫腔内移植。

用人/啮齿类体细胞杂种系及荧光原位杂交将人类新基因ZNF191定位于染色体18q12.1

本文以锌指蛋白ZNF191全长cDNA为探针,与人/啮齿类体细胞杂种系DNA杂交,将这个新的人类锌指基因定位于18号染色体。又用该cDNA筛选人基因组DNA lambda/DASH文库,以获得的DNA片段为探针,进行人染色体荧光原位杂交(FISH)分析,将ZNF191基因精细定位在染色体18q 12.1区带。依据有关遗传连锁分析和等位基因荧光原位杂交(FISH),将ZNF191精确定位于人染色体18q12.1。通过遗传连锁及染色体杂合性丢失分析.目前已知多种遗传病和肿瘤与这个区域相关。因此,ZNF191基因可作为这些疾病或肿瘤的候选相关基因。

中国春phlb突变体与多倍体Aegilops杂种F_1回交植株(BC_1F_1)的细胞学研究

中国春 phlb突变体与 5个多倍体 Aegilops的杂种 F1 用普通小麦进行回交 ,并对回交一代 (BC1 F1 )的细胞学进行了研究。结果表明 ,BC1 F1 植株花粉母细胞最高染色体数 56条 ,最低 35条 ,一般情况下 phlb基因可以增加 BC1 F1 植株的染色体数 (不是所有组合 ) ,但不能增加染色体配对水平。杂种 F1 回交时有效雌配子最高染色体数在含有 phlb基因组合中高于不含 ph1 b基因的组合 ,但最低染色体数目相等 ,且含有 2 1条染色体雌配子最具有竞争力。同时也证明 ,回交的成功并不取决于杂种 F1 通过重建分裂 (restitution division)