Objective To investigate the effects ofendothelin-1 (ET-1) and endothelin-3 (ET-3) on the expression of transformation growth factor-beta 1 (TGF-β1) and phosphorylation of Smad 3 in malignant melanoma cell line, A375. Methods Cultured A375 cells were classified into 5 groups, i.e. control group (no stimulation), ET-1 group (stimulated with ET-1), ET-1+BQ123 group (treated with ET-1 and BQ123),ET-1 + BQ788 group (treated with ET-1 and BQ788), ET-3 group (stimulated with ET-3), to receive different stimulation. The working concentrations were 0, 0.1, 1, 10, 100 nmol/L for ET-1 and ET-3, 10 μmol/L for BQ123 and BQ788. After another 12- and 24-hour culture, ELISA, RT-PCR and Western blot were used to detect the expression of TGF-β1 protein and mRNA as well as phosphorylated Smad 3 (P-Smad 3). Results The expression of TGF-β1 in A375 cells was up-regulated by ET-1, but down-regulated by ET-3, and both of the effects were in a concentration-dependent manner. Under the stimulation with ET-1 and ET-3 of 100 nmol/L, the level of TGF-β1 reached 1289.38 ± 89.42 ng/L per 105 cells and 85.09 ± 9.37 ng/L per 105 cells, respectively, significantly different from that in unstimulated cells (both P < 0.05). BQ123 signifi-cantly blocked the up-regnlatory effect of ET-1 on the expression TGF-β1 protein(P < 0.05), but BQ788 had no significant influence on the effect, so was the case with TGF-β1 mRNA. Western blot revealed that ET-1significantly elevated the expression of P-Smad 3 in A375 cells (P <0.05), and the elevation was significantly inhibited by BQ123, but not by BQ788. The expression of P-Smad 3 was statistically decreased by ET-3 in A375 cells (P <0.05). Conclusions The expression of TGF-β1 could be enhanced by ET-1, but suppressed by ET-3. It is likely that endothelin receptor A mediates the phosphorylation of Smad 3 induced by ET-1.

The expressions of p-STAT3 and osteopontin in 22 cases of normal nevi and 43 cases of malignant melanoma were immunohistochemically detected,and the correlation between p-STAT3 and osteopontin in malignant melanoma and the correlations of p-STAT3 (or osteopontin) with invasion,metastasis and thickness of malignant melanoma were examined.The results showed p-STAT3 was expressed in 2 of 22 cases of normal nevi and 30 of 43 cases of malignant melanoma,while osteopontin was expressed in 3 cases of normal nevi and 29 cases of malignant melanoma.The expressions of p-STAT3 and osteopontin in melanoma were significantly higher than that in benign nevi.There existed significant correlations between the expression of p-STAT3 and that of osteopontin in melanoma.Furthermore,the expression rates of p-STAT3 were significantly higher in invasive or metastatic melanomas than that their non-invasive or non-metastatic counterparts,and the expression rates of osteopontin were significantly higher in invasive melanomas than that in non-invasive ones.It is concluded that p-STAT3 and osteopontin may play important roles in the pathogenesis of malignant melanoma.

A site-directed mutant DNA fragment was synthesized and transfected into clinical Neisseria gonorrhoeae (NG) stains to construct the transformants that contained the corresponding mutagenesis of regulation region of mtrR gene. According to the technique of gene splicing by overlap extension (SOEing), a DNA segment with specific mutagenesis was constructed by two-step polymerase chain reaction (PCR). The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced. By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains, 2 of these were not compatible completely. The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat sequence localized within the mtrR promoter. It can be confirmed that the fragments EF are the specifically designed mutant fragments.
Bacterial Proteins/*genetics ; DNA Fragmentation ; DNA, Bacterial/genetics ; Mutagenesis, Site-Directed ; Neisseria gonorrhoeae/*genetics ; Neisseria gonorrhoeae/metabolism ; Recombination, Genetic ; Repressor Proteins/*genetics ; Sequence Deletion ; Transfection ; Transformation, Bacterial

In order to investigate the expression of endothelin receptor B (ETR-B) in human malignant melanoma (MM) cells A375 and SK-mel-1 and the proliferative effects of endothelin 3 (ET3) on A375 cells, RT-PCR was applied to detect the expression of ETR-B gene in human MM cells A375 and SK-mel-1. MTT method was used to evaluate the growth enhancing effects of ET3 on A375 cell line in vitro. The results showed that ETR-B gene was expressed in both MM A375 and SK-mel-1 cells. ET3 had stronger ability to enhance the proliferation of A375 cells in vitro in a concentration-dependent manner. It was suggested that ET3/ETR-B might play an important proliferative role in MM.
Cell Line, Tumor ; Cell Proliferation/*drug effects ; Endothelin-3/*pharmacology ; Melanoma/*metabolism ; Melanoma/*pathology ; Receptor, Endothelin B/*metabolism ; Reverse Transcriptase Polymerase Chain Reaction

In order to analyze the in vivo expression of Candida albicans secreted aspartyl proteinases (SAP) in human vaginal infection, the vaginal secretion from 29 human subjects was collected by vaginal swab, and the expression of SAP1-SAP6 was detected by reverse-transcriptase polymerase chain reaction using specific primer sets. It was found that Sap2 and Sap5 were the most common genes expressed during infection; Sap3 and Sap4 were detected in all subjects and all 6 SAP genes were simultaneously expressed in some patients with vaginal candidiasis. It was suggested that the SAP family is expressed by Candida albicans during infection in human and that Candida albicans infection is associated with the differential expression of individual SAP genes which may be involved in the pathogenesis of vaginal candidiasis.

In order to analyze the in vivo expression of Candida albicans secreted aspartyl proteinases (SAP) in human vaginal infection, the vaginal secretion from 29 human subjects was collected by vaginal swab, and the expression of SAP1-SAP6 was detected by reverse-transcriptase polymerase chain reaction using specific primer sets. It was found that Sap2 and Sap5 were the most common genes expressed during infection; Sap3 and Sap4 were detected in all subjects and all 6 SAP genes were simultaneously expressed in some patients with vaginal candidiasis. It was suggested that the SAP family is expressed by Candida albicans during infection in human and that Candida albicans infection is associated with the differential expression of individual SAP genes which may be involved in the pathogenesis of vaginal candidiasis.

In order to study the expression of intedeukin-22 (IL-22) and S100A7, A8, A9 mRNA in the skin lesions of patients with psoriasis vulgaris and their relationship, the biopsies were taken from skin lesions in 35 patients with psoriasis vulgaris and the skin of 16 normal controls, and the expres- sion levels of IL-22 and S 100A7, A8 and A9 mRNA were detected by semi-quantitative RT-PCR. The results showed that (1) IL-22 and SI00A8, A9 mRNA were positively expressed in the psoriatic skin lesions but negatively expressed in the normal controls; The expression level of S100A7 was (1.133±0.040) in the psoriatic skin lesions, significantly higher than that in the normal controls (0.744±0.037, P<0.01). (2) There were significantly positive correlations between the expression of IL-22/S100A7 mRNA, IL-22/S100A8 mRNA, IL-22/S100A9 mRNA in the psoriasis vulgaris (r1=0.543, r2=0.774, r3=0.621, P<0.01). It was concluded that IL-22 and S100A7, A8, A9 might play important roles in the occurrence and progression of psoriasis.

A site-directed mutant DNA fragment was synthesized and transfected into clinical Neisseria Gonorrhoeae (NG) stains to construct the transformants that contained the corresponding mutagenesis of regulation region of mtrR gene. According to the technique of gene splicing by over-lap extension (SOEing), a DNA segment with specific mutagenesis was constructed by two-step po-lymerase chain reaction (PCR). The mutation fragments EF could be used for the next experiment in which the mutation NG strains were induced. By comparing the recombinant EF fragments to the corresponding DNA fragments of clinical NG strains, 2 of these were not compatible completely. The results of sequencing revealed that there was a 9 bp deletion between the 45 to 54 inverted repeat se-quence localized within the mtrR promoter. It can be confirmed that the fragments EF are the specifi-cally designed mutant fragments.

In order to investigate the expression of endothelin receptor B (ETR-B) in human ma-lignant melanoma (MM) cells A375 and SK-mel-1 and the proliferative effects of endothelin 3 (ET3) on A375 cells, RT-PCR was applied to detect the expression of ETR-B gene in human MM cells A375 and SK-mel-1. MTT method was used to evaluate the growth enhancing effects of ET3 on A375 cell line in vitro. The results showed that ETR-B gene was expressed in both MM A375 and SK-mel-1 cells. ET3 had stronger ability to enhance the proliferation of A375 cells in vitro in a con- centration-dependent manner. It was suggested that ET3/ETR-B might play an important proliferative role in MM.

To study the relationship between mutation of the inverted repeat sequence (IR) in the multiple transferable resistant system (mtr) of Neisseria gonorrhoeae (NG) and its multiple antibiotic resistance, minimal inhibitory concentrations (MICs) for the clinically isolated strains were tested by agar-dilution-method. The mtr system's IR gene of NG was sequenced after amplification by polymerase chain reaction (PCR). Either two susceptive or five penicillin-resistant strains had no base mutation in IR gene, while all of the 13 strains with multiple-antibiotic-resistance had a single-base deletion (A/T). The result suggests that a single-base deletion of the thirteen-base IR sequence in mtr system of NG might result in multiple antibiotic resistance but is not associated with single antibiotic resistance.