Study of conformational properties of solid phase synthesized ovine kisspeptin-14 using Circular Dichroism spectroscopy.

Kisspeptins are peptide products of Kiss-1 gene and have been substantially associated with the initiation of puberty by virtue of their ability to cause pulsatile release of GnRH. Kisspeptin consists of 54 amino acids domain called metastin and its biological activity may be localized to the C-terminal (C-10, C-13, and C-14) segments. Kisspeptin binds to its cognate receptor GPR54 in the hypothalamic neurons and it is a G-coupled membrane receptor. This study is an attempt to understand the tentative conformation of the peptides in its native membrane mimicking environment. A 14 amino-acid derivative of kisspeptin (Asp-58-Val59-Ser60-Ala61-Tyr62-Asn63-Trp64-Asn65-Ser66-Phe67-Gly68-Leu69-Arg70-Tyr71NH2) was synthesized by f-moc (9-fluorenyl methoxy carbonyl) solid phase synthesis strategy. The synthetic peptide was cleaved and purified by Reverse phase-HPLC. CD spectroscopic analysis of secondary structure of the peptide revealed random coil disordered conformation in the aqueous environment. However, the peptide adopted more ordered β-sheet conformation in the solvents such as TFE and HFIP.

Effects of 5-Aza-dC on KISS1 gene expression and the abilities of invasion and migration of human colorectal cancer cell line HCT116 / 肿瘤

Objective: To investigate the effects of methylation of KISS1 gene promoter and KISS1 expression on biological characteristics of colorectal cancer HCT116 cells induced by methyltransferase inhibitor 5-aza-2′-deoxycytidine (5-Aza-dC). Methods: The promoter methylation status of KISS1 gene and its mRNA and protein expressions in HCT116 cells were detected by methylation-specific PCR, real-time fluorogenic quantitative-PCR and Western blotting, respectively; after treatment with 5-Aza-dC in vitro. The abilities of invasion and migration of HCT116 cells were detected by Transwell assay, and the cell proliferation was detected by Cell Counting Kit-8 (CCK-8). Results: The demethylation of KISS1 promoter was induced after treatment with 5-Aza-dC. The expressions of KISS1 mRNA and protein in HCT116 cells were significantly increased in a dose-dependent manner after treatment with different doses of 5-Aza-dC for 5 days as compared with those without treatment with 5-Aza-dC (P 0.05). The abilities of invasion and migration of HCT116 cells after 5-Aza-dC treatment were also reduced (P < 0.05). Conclusion: The DNA methyltransferase inhibitor 5-Aza-dC can reverse the methylation of KISS1 promoter, and reduce the abilities of invasion and migration of HCT116 cells by up-regulating the expression of KISS1. Copyright© 2014 by TUMOR.

Effect of Kiss-1 gene promoter methylation on its expression in colorectal carcinoma tissue and its clinical significance / 吉林大学学报(医学版)

Objective To research the effect of the Kiss-1 gene promoter methylation on the Kiss-1 gene expression in colorectal carcinoma tissue,and to analyze the relationship between the Kiss-1 gene methylation and the clinical pathological features of colorectal carcinoma and its clinical significance.Methods The Kiss-1 gene promotor region methylation,Kiss-1 gene mRNA and protein expressions were detected respectively by methylation-specific PCR, Real-time PCR and Western blotting method in 126 cases of colorectal carcinoma tissue and para-cacinoma normal colorectal tissue.Results The positive rate of Kiss-1 gene methylation in colorectal carcinoma tissue (83.33%)was significantly higher than that in normal tissue (30.16%)(P0.05 ). Conclusion The Kiss-1 gene promoter methylation in colorectal carcinoma tissue is associated with the Kiss-1 gene expression level and the malignant characteristics of colorectal carcinoma;Kiss-1 gene promoter methylation may be used as a reference indicator for predicting the risk of metastasis of colorectal carcinoma.

KISS1 Gene Polymorphisms in Korean Girls with Central Precocious Puberty

Kisspeptin/G-protein couple receptor-54 (GPR54) system plays a key role in the activation of the gonadotropic axis at puberty. Central precocious puberty (CPP) is caused by the premature activation of hypothalamic gonadotropin-releasing hormone secretion. This study was aimed to identify KISS1 gene variations and to investigate the associations between KISS1 gene variations and CPP in Korean girls. All coding exons of KISS1 gene were sequenced in Korean girls with CPP (n = 143) and their healthy controls (n = 101). Nine polymorphisms were identified in KISS1 gene. A novel single-nucleotide polymorphism (SNP), 55648176 T/G, was identified for the first time. SNP 55648184 C/G and 55648186 -/T were detected more frequently in CPP group than in control group. SNP 55648176 T/G was detected less frequently in CPP group than in control group. Haplotype GGGC-ACCC was detected less frequently in CPP group. The genetic variations of KISS1 gene can be contributing factors of development of CPP. The association between the gene variations and CPP should be validated by further evidence obtained from large-scaled and functional studies.

KISS1 Gene Polymorphisms in Korean Girls with Central Precocious Puberty

Kisspeptin/G-protein couple receptor-54 (GPR54) system plays a key role in the activation of the gonadotropic axis at puberty. Central precocious puberty (CPP) is caused by the premature activation of hypothalamic gonadotropin-releasing hormone secretion. This study was aimed to identify KISS1 gene variations and to investigate the associations between KISS1 gene variations and CPP in Korean girls. All coding exons of KISS1 gene were sequenced in Korean girls with CPP (n = 143) and their healthy controls (n = 101). Nine polymorphisms were identified in KISS1 gene. A novel single-nucleotide polymorphism (SNP), 55648176 T/G, was identified for the first time. SNP 55648184 C/G and 55648186 -/T were detected more frequently in CPP group than in control group. SNP 55648176 T/G was detected less frequently in CPP group than in control group. Haplotype GGGC-ACCC was detected less frequently in CPP group. The genetic variations of KISS1 gene can be contributing factors of development of CPP. The association between the gene variations and CPP should be validated by further evidence obtained from large-scaled and functional studies.

Developmental changes in the expression of Kiss1 gene and estrogen receptor α gene in hypothalamus of female Sprague-Dawley rats / 中华实用儿科临床杂志

Objective To investigate the function of Kiss1 gene and estrogen receptor α gene (ERα gene) in puberty of rats,by detecting the expressions of Kiss1 mRNA and ERα mRNA in the hypothalamus and the serum luteinizing hormone (LH) and estradiol (E2) level of female Sprague-Dawley (SD) rats at various stage of development with Real-time PCR and enzyme-linked immunosorbent assay(ELISA).Methods Thirty-five female SD rats of 3 days were weaned on postnatal(PND)22 and then the vaginal opening condition was observed daily.The rats were sacrificed at PND 15(juvenile group,n =19) and PND 35 (pubertal group,n =16).The hypothalamus were segregated and the serum were extracted from heart blood.All of the samples were stored at-80 ℃ prepared.Then the mRNA were extracted from the hypothalamus and the cDNA obtained by reverse transcription were tested with real-time PCR.The relative mRNA expression level of Kiss1 gene and ERα gene were calculated.Results 1.Entire level:it was found that the pubertal group vaginal opening time was (32.1 ± 1.0) days,while the juvenile group was not found with vaginal opening until sacrificed.2.Real-time PCR:the expressions of Kiss1 and ERα gene were significantly increased in pubertal group (Kissl gene:5.39-± 2.52,ERα gene:1.57 ±1.87) compared with juvenile group(Kiss1 gene:1.06 ± 1.09,ERα gene:0.59-± 0.68),and the differences were statistically significant (all P ＜ 0.001).3.ELISA:the serum LH and E2 in pubertal group [LH (11.61 ± 0.95) IU/L,E2 (167.53 ± 31.09) ng/L] were significantly higher than LH [(5.46-± 1.89)IU/L] and E2 [(58.59 ± 29.96) ng/L] in juvenile group,and the differences were statistically significant (all P ＜0.001).Conclusion Kiss1 gene and ERα gene are involved in the start of the sexual development of female SD rat.

Serum Kisspeptin Levels in Korean Girls with Central Precocious Puberty

Central precocious puberty (CPP) is caused by premature activation of hypothalamic gonadotropin-releasing hormone (GnRH) secretion. Kisspeptin and G-protein coupled receptor-54 system is the essential gatekeeper of the reproductive system, playing a key role in the activation of the gonadotropic axis at puberty. We aimed to determine whether serum kisspeptin may function as a marker for CPP by investigating serum kisspeptin levels in Korean girls with CPP and their prepubertal controls. Serum kisspeptin levels of Korean girls with CPP (n = 30) and age-matched healthy prepubertal controls (n = 30) were measured with a competitive enzyme immunoassay. Serum kisspeptin levels were significantly higher in CPP group than in control group (4.61 +/- 1.78 vs 2.15 +/- 1.52 pM/L, P < 0.001). Serum kisspeptin was positively correlated with peak luteinizing hormone (LH), peak/basal LH ratio and peak LH/follicular-stimulating hormone (FSH) ratio during GnRH stimulation test. CPP is supposed to be triggered by premature increase of kisspeptin. Serum kisspeptin may be used as a marker of CPP. Further studies on KISS1 gene polymorphisms leading to higher risk of premature increase of kisspeptin and upstream regulator of kisspeptin are also needed.

Relationship between KISS-1 Gene and Metastasis of Bladder Carcinoma and the Effect of Stable Expression of KISS-1 Gene on the Invasion of Bladder Carcinoma Cells / 中国医科大学学报

Objective To explore the relationship between KISS-1 gene and metastasis of bladder carcinoma,and to study the effect of the stable expression of KISS-1 gene on the invasion of bladder carcinoma cell line T24.Methods Fluorescent quantitative PCR was used to detect the expression of KISS-1 mRNA in primary bladder carcinoma without metastasis and primary bladder carcinoma with metastasis.Recombinant vector pIRES2-AKS-1 was constructed and transfected into T24 cells.Single clone of stably transfected cells was screened,and the changes in the invasive ability of T24 cells was detected after transfection.Results The expression level of KISS-1 mRNA in primary bladder carcinoma with metastasis was significantly lower than that in primary bladder carcinoma without metastasis(P＜0.05).The expression of KISS-1 protein in the single clone of stably transfected cells increased significantly,and the invasive ability significantly decreased(P＜0.05).Conclusion KISS-1 gene is correlated with the metastasis of bladder carcinoma,and the up-regulated expression of KISS-1 gene can inhibite the invasiveness of T24 cell line.

Kiss-1 gene and metastasis of malignant tumor / 国际肿瘤学杂志

Kiss-1 gene is an anti-oncogene which is correlative with the genesis and progress of various human malignant tumors.it plays an important role in process of tumor invasion and metastasis. Kiss-1 gene is associated closely with metastasis of melanoma,breast cancer,gastric carcinoma,esophageal cancer and differentiated thyroid carcinoma and so on,but the mechanism is not fully elucidated. Therefore,the detection of Kiss-1 gene expression will be valuable for the treatment and prognosis of malignant tumor.