甲基化的

Methylation is negative correlation with genetic transcription , and the mechanism is probably as follows : directly interfere the combination of specific transcripton and recognition site of each promoter ; mediated transcription inhibition by change the construction of chromatin; induced gene silencing by combination of methylation site and transcription inhibition. P16 gene is also called multiple tumor supresser gene , which is the best easily to methylate in the anti-oncogenes. P16 gene locates in 9p21 of mankind-chromatosome , and it's total length is 8.5kb .

甲基化与基因转录呈负相关，其机制可能是[3]：直接干扰特异的转录子和各自启动子识别位点的结合；通过改变染色质结构，介导转录抑制；甲基化DNA位点直接与转录抑制子结合，诱导基因沉默。p16基因又称为多肿瘤抑制基因( multiple tumor suppressor 1 ，MTS1) [4] ，是肺癌中最易发生甲基化的抑癌基因，该基因位于人类染色体9p21上，全长8.5kb ，由两个内含子和三个外显子组成。

The inhibitor for DNA methyltransferase, 5-azacytidine (5-azaC), can demethylate the methylated DNA and restore transcription of genes. High dose homocystine can mediat DNA methylation and suppress gene expression.

应用甲基转移酶抑制剂5-氮杂胞苷(5-azacytidine， 5-azaC)可以使甲基化的启动子去甲基化，启动基因重新转录；高浓度同型半胱氨酸(homocystine， Hcy)可以介导基因甲基化而抑制其表达。

Although the biological significance of DNA methylation has been recognized to some extent, the mechanisms of DNA methylation regulation and of the establishment of tissue-specific DNA methylation pattern in somatic cells are still unclear, since the knowledge of the enzymes responsible for de novo DNA methylation and demethylation of DNA is very limited and up to now only two functional DNA methyltransferases in mammals have been cloned.

目前，虽然对DNA甲基化的作用已有一定认识，但DNA甲基化的调节以及发育过程中组织特异的DNA甲基化谱的建立机制还不清楚。问题主要在于对催化重新甲基化和去甲基化反应的酶的了解很少。至今仅克隆出两种有功能的哺乳动物DNA甲基转移酶。

The complexity of the methylarginine mark is enhanced by the ability of this residue to be methylated in three different ways on the guanidino group: monomethylated, symmetrically dimethylated and asymmetrically dimethylated, each of which has potentially different functional consequences.

根据将S-腺苷甲硫氨酸(S-adenosylmethionine，AdoMet)上的甲基转移到精氨酸的胍基氮上产生甲基化的不同方式，最终可以分为三类：单甲基化、对称性双甲基化和非对称性双甲基化。

The remainder 12 patients were fourd Id4 unmethylated, 1 case out of whom relapsed within the next 3-month of follow-up (8.33%), while 10 out of 20 patients (50%) with 1d4 methylation relapsed within the same follow-up period.

结果发现，32例完全缓解的ALL患者中20例(62.5%)DNA抑制因子4呈甲基化。12例DNA抑制因子4呈非甲基化的患者中只有1例3个月内复发，复发率8.33%，20例DNA抑制因子4呈甲基化状态的患者中10例3个月内复发，复发率50%。

The gene chip detecting methylation changes of 3 CpG in promoter region of p16 gene was constructed by designing a pair of probes which contain one methylated and one unmethylated probes. This pair of probes was used to detect 3 consecutive sites of CpG island in p16 gene.

设计1组特殊荧光标记探针以构建1种检测p16基因启动子区3个CpG位点甲基化改变的芯片，特殊荧光标记探针包括1对非甲基化探针和甲基化探针，检测相邻的3个CpG位点甲基化的程度。

Methods genomic dna was extracted from different stages of malignant transformation and tumorigenicity in inoculated athymic mouse 16hbe cells induced by cadmium chloride and methylating status of genome p16 gene promoter was observed with methylation-specific pcr and then compared with the controls.

从各组cdcl2恶性转化不同阶段及接种裸鼠成瘤的16hbe细胞中提取全基因组dna，采取甲基化特异性pcr法(methylation-specific pcr，msp)检测该基因组p16基因启动子区的甲基化状况，与非转化的16hbe对照细胞进行比较，并用去甲基化因子5-azac (5-aza-2'deoxycytidine)处理有异常甲基化的细胞。

E-cadherin methylation may play an important role in the carcinogenesis of colon carcinoma cells and can re-express after the treatment with 5-Aza-CdR.

E-cadherin基因启动子区异常甲基化是结肠癌发生、发展的重要机制之一，5-Aza-CdR能使甲基化的E-cadherin去甲基化修饰并重新表达。

Theoretically, re-expression of tumor suppressor genes by demethylating agents may contribute to inhibiting the development of tumor. It has been suggested that DNA hypermethylation results in resistance to chemotherapy and consequently reduces the efficacy of chemotherapeutic treatment.

由于高度甲基化而暂停表达的抑癌基因，如果能应用去甲基化制剂逆转甲基化的异常状态，使之重获表达，理论上即可发挥其抑制肿瘤细胞生长的功能。

Krogan N J, Kim M, Tong A, et al Methylation of histone H3 by Set2 in Saccharomyces cerevisiae is linked to transcriptional elongation by RNA polymerase ||. Mol Cell Biol, 2003, 12(2):476-487[12] J Biol Chem.

表达基因转录起始下游的局限性H3-K9的三甲基化不在启动子高甲基化的区域，H3-K9的三甲基化耦合于RNA聚和酶II在沉默基因中具有一致性。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。