Genotype distribution of T cell receptor β gene in Indonesian nasopharyngeal carcinoma patients.

Background: Nasopharyngeal carcinoma (NPC) is a multifactorial genetic disease, characteristically endemic and shows considerable differences in its geographical distribution. Besides infection with EBV, genetic factors such as polymorphisms of TCR-β gene contribute to the incidence of NPC. This study investigates the association of TCR-β gene polymorphisms with individual susceptibility to develop NPC in Indonesian ethnic groups. Methods: The study was carried out by the PCR-RFLP method using Bgl II restriction enzyme to digest TCR-β gene. The PCR-RFLP analysis of TCR-β gene was used to determine allotypes of TCR-β gene in NPC patients and control among ethnic Chinese and indigenous groups in the population of Indonesia. Results: The results indicate that the distribution of TCR-β gene allotypes between NPC patients and controls are not significantly different (p > 0.05); however, the frequency of A allele tends to increase in NPC patients. The distribution of TCR-β gene allotypes between Chinese ethnic group was not signifi cantly different from indigenous groups (p > 0.05). Conclusion: The distribution of TCR-β gene allele between NPC group and control groups showed no difference. The distribution of TCR-β gene between ethnic Chinese and indigenous groups showed no difference. Polymorphisms of TCR-β gene are not associated with NPC and ethnic groups in Indonesian population.

Development of bioassay for pathogenecity testing of Ureaplasma urealyticum as part of host-pathogen communication.

Bioassay of Ureaplasma urealyticum is necessary for detection as well as determination of pathogenic factors in order to understand the pathogenesis of diseases associate with ureaplasma infection. Cultivation and verification of ureaplasma is the first step of this study in the purpose of discovering sensitive method for ureaplasma detection. Cultivation of ureaplasma either in liquid or in solid media are able to detect the existence of ureaplasma in samples analyzed. However, application of PCR using specific primers to be compatible with urease gene (ure) would confirm the presence of ureaplasma. The pathogenicity of ureaplasma is potentially monitored using reporter gene as a marker for gene expression. IceC was chosen as reporter gene for ureaplasma pathogenic determination as the gene has great sensitivity, easily detectable and quantitated in simple method of ice nucleation assay. Transposon 916 (Tn916) was selected as a vector for iceC gene to transform ureaplasma. The application of recombinant Tn916-iceC which is considered as pUI, allow detection of ureaplasma activities when transform ureaplasma is tested by ice nucleation assay. It was expected that ureaplasma transformation is the manifestation of mutagenesis which interfere genes responsible for bacterial pathogenicity, in order pathogenesis of bacterial infection to be analyzed accurately. IgA1 protease is considered to be an important factor for ureaplasma pathogenicity as the enzyme is required for successful colonization. Identification of iga gene and determination of IgA1 protease activity are important for understanding the pathogenesis of ureaplasma infection. Putative iga gene of Mycoplasma genitalium was used as a reference to identify the presence of iga nucleotide sequence in U. urealyticum. Convincing evidence were obtained after PCR amplification of ureaplasma DNA using primers designed to be compatible with putative iga gene of M. genitalium followed by the discovery of 100% sequence homology of amplified ureaplasma iga gene and iga gene of M. genitalium mentioned in establish data. IgA1 protease activity of U. urealytium has been detectable in the cell rather than in media culture, suggesting that IgA1 protease is not secreted out of cell. It was proofed that IgA1 protease is membrane bound enzyme capable of digesting IgA1 in mucosal tissues of various organs and considered as potential virulence factor for ureaplasma that cause disease or gain entry to mucosal membrane. The existence of IgA1 protease activity in bacterial plasma membrane would have implication in ureaplasma management such as diagnosis and therapy of ureaplasma infection.

The association of CAG repeat length polymorphisms of androgen receptor gene and spermatogenesis impairment in several Indonesian men.

Spermatogenesis impairment is the main cause of infertility in men. Androgen is believed to play a critical role in regulating spermatogenesis. Androgen acts by binding to the androgen receptor (AR) which is a protein regulator of DNA transcription. Exon 1 of AR gene contains a CAG repeat length polymorphism and it is believed to interfere AR function. This study includes DNA isolation from peripheral blood and amplification of CAG repeat fragments by PCR method. CAG repeat lengths were determined by electrophoresis on 6% denaturing gel polyacrylamide. We found that the mean CAG repeat lengths were 24,3 ± 3,4 in oligozoospermic/azoospermic men and 22,7 ± 2,7 in normozoospermic men. The difference in CAG repeat length between the two groups was statistically significant (p = 0,031, t-test). Nevertheless, there was no correlation between CAG repeat lengths and sperms concentration (rs = -0,038; p = 0,775). This result suggest that the expansion of CAG repeat length was not the main cause of spermatogenesis impairment.

Single nucleotide polymorphisms of follicle-stimulating hormone receptor promoter and their impacts to the promoter activities.

Women of reproductive ages are varies in their responses to exogenous FSH stimulations. The difference of FSHR genotype due to the polymorphisms in exon 10 is one of its significant factors. To know further whether the core promoter of FSHR is also polymorphic and to know whether those polymorphisms influence the promoter activity, we did polymorphism screening of FSHR promoter to 262 women undergoing IVF/ICSI, followed by functional study to know the impact of polymorphisms to the promoter activity. This study indicated that the core promoter of human FSHR is polymorphic. We found five SNPs at positions –29, –37, –114, –123 and –138 in addition to the variety number of adenines. Polymorphism at position –123 significantly decreased the promoter activity, in contrast, polymorphism at position –37 and –138 significantly increased the promoter activity, whereas polymorphism at position –29, –114 and short adenines stretch did not significantly influence the promoter activity. The differences of the promoter activities due to polymorphisms might change the ovarian sensitivity to FSH.

The expression of follicle-stimulating hormone receptor in ovary and testis.

Follicle-stimulating hormone receptor (FSHR) is exclusively expressed in granulose cells of the ovary and Sertoli cells of the testis. The highly cell-specific of gene expression revealed that transcriptional events unique to these two cell types are responsible for activation of the FSHR gene. Even though its mechanisms are still unclear, several progress regarding the mechanism that control its basal transcription and regulation has been made. It has been identified several important elements that responsible for the transcription of the TATA-less FSHR gene such as: E box element (CACG(A)TG, –124/–119), an inverted GATA (TATC, –88/–85), E2F (TTTCGCG, –45/–39), and regulator element-3 (–197/–171). The functional studies shown that mutations through these regulatory elements significantly decrease the promoter function with greatest impact detected when mutation was done in E-box element. The site-specific CpG methylation within the core promoter seems play an important role in the regulation of rat and mouse FSHR gene expression.