Cypermethrin inhibits interleukin-6-induced androgen receptor transactivation through signal transducer and activator of transcription 3.

The insecticide cypermethrin has been considered as an endocrine-disrupting chemicals (EDCs) with anti-androgenic activity by interfering with interleukin-6 (IL-6) - induced ligand-independent AR signaling. The purpose of this study was to clarify whether the signal transducer and activator of transcription 3 (STAT3) was involved in the antagonism effect of cypermethrin. In this study, the Western blot was to test the level of STAT3 phosphorylation and the mammalian two-hybrid assay was developed to assess the AR-STAT3 interaction. The date showed that IL-6 increased the phosphorylation level of STAT3 and enhanced the AR-STAT3 interaction. Cypermethrin did not affect the phosphorylation level of STAT3 induced by IL-6, while suppressed the AR-STAT3 interaction induced by IL-6 significantly at the concentration of 10-5 M (p < 0.05). The study indicates cypermethrin inhibits IL-6-induced AR signaling by suppressing the interaction between the AR and STAT3. We provide a novel mechanism of cypermethrin-mediated antagonism on IL-6-induced AR activation associated with STAT3.

Inhibition effect of cypermethrin mediated by co-regulators SRC-1 and SMRT in interleukin-6-induced androgen receptor activation.

It is hypothesized that the pesticide cypermethrin may induce androgen receptor (AR) antagonism via ligand-independent mechanisms. The Real-Time Cell Analysis (RTCA) iCELLigence system was used to investigate the inhibitory effect of cypermethrin on interleukin-6 (IL-6)-induced ligand-independent LNCaP cell growth. Then, the mammalian two-hybrid assays were applied to clarify whether the mechanism of IL-6-induced AR antagonism of cypermethrin was associated with the interactions of the AR and co-activator steroid receptor co-activator-1 (SRC-1) and co-repressor silencing mediator for retinoid and thyroid hormone receptors (SMRT). Cypermethrin inhibited the LNCaP cell growth induced by IL-6. The interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 were suppressed by cypermethrin. The results indicate that the IL-6-mediated AR antagonism induced by cypermethrin is related to repress the recruitment of co-regulators SRC-1 and SMRT to the AR in a ligand-independent manner. Inhibition of the interactions of AR-SRC-1 and AR-SMRT mediated by IL-6 contributes to the AR antagonism induced by cypermethrin.

The co-regulators SRC-1 and SMRT are involved in interleukin-6-induced androgen receptor activation.

BACKGROUND: The androgen receptor (AR) can be stimulated by interleukin-6 (IL-6) in the absence of androgens to induce prostate cancer progression. The purpose of this study was to investigate whether the co-activator steroid receptor coactivator-1 (SRC-1) and co-repressor silencing mediator for retinoid and thyroid hormone receptors (SMRT) are involved in IL-6-induced AR activation. METHODS: The effects of IL-6 on LNCaP cell proliferation were monitored using real-time cell analysis (RTCA) iCELLigence system. The impacts of IL-6 on the association of the AR with SRC-1 and SMRT were investigated using the mammalian two-hybrid assay. RESULTS: IL-6 increased the proliferation of LNCaP cells with maximal induction at 50 ng/mL. The AR-SRC-1interaction was enhanced by IL-6, with maximal induction at the concentration of 50 ng/mL (P<0.05). IL-6 decreased the AR-SMRT interaction and a marked reduction was detected at 50 ng/mL (P<0.05). CONCLUSIONS: IL-6 enhances LNCaP cells proliferation, which suggests that IL-6 might cause AR-positive prostate cancer growth through activation of the AR. The mechanism of IL-6-induced AR activation is mediated through enhancing AR-SRC-1 interaction and inhibiting AR-SMRT interaction. We have shown a significant role for SRC-1 and SMRT in modulating IL-6-induced AR transactivation.

Identification of susceptibility genes in non-syndromic cleft lip with or without cleft palate using whole-exome sequencing

BACKGROUND: Non-syndromic cleft lip with or without cleft palate (NSCL/P) is among the most common congenital malformations. The etiology of NSCL/P remains poorly characterized owing to its complex genetic heterogeneity. The objective of this study was to identify genetic variants that increase susceptibility to NSCL/P. MATERIAL AND METHODS: Whole-exome sequencing (WES) was performed in 8 fetuses with NSCL/P in China. Bioinformatics analysis was performed using commercially available software. Variants detected by WES were validated by Sanger sequencing. RESULTS: By filtering out synonymous variants in exons, we identified average 8575 nonsynonymous single nucleotide variants (SNVs). We subsequently compared the SNVs against public databases including NCBI dbSNP build 135 and 1000 Genomes Project and obtained an average of 203 SNVs. Total 12 reported candidate genes were verified by Sanger sequencing. Sanger sequencing also confirmed 16 novel SNVs shared by two or more samples. CONCLUSIONS: We have found and confirmed 16 susceptibility genes responsible for NSCL/P, which may play important role in the etiology of NSCL/P. The susceptibility genes identified in this study will not only be useful in revealing the etiology of NSCL/P but also in diagnosis and treatment of the patients with NSCL/P

Identification of susceptibility genes in non-syndromic cleft lip with or without cleft palate using whole-exome sequencing.

BACKGROUND: Non-syndromic cleft lip with or without cleft palate (NSCL/P) is among the most common congenital malformations. The etiology of NSCL/P remains poorly characterized owing to its complex genetic heterogeneity. The objective of this study was to identify genetic variants that increase susceptibility to NSCL/P. MATERIAL AND METHODS: Whole-exome sequencing (WES) was performed in 8 fetuses with NSCL/P in China. Bioinformatics analysis was performed using commercially available software. Variants detected by WES were validated by Sanger sequencing. RESULTS: By filtering out synonymous variants in exons, we identified average 8575 nonsynonymous single nucleotide variants (SNVs). We subsequently compared the SNVs against public databases including NCBI dbSNP build 135 and 1000 Genomes Project and obtained an average of 203 SNVs. Total 12 reported candidate genes were verified by Sanger sequencing. Sanger sequencing also confirmed 16 novel SNVs shared by two or more samples. CONCLUSIONS: We have found and confirmed 16 susceptibility genes responsible for NSCL/P, which may play important role in the etiology of NSCL/P. The susceptibility genes identified in this study will not only be useful in revealing the etiology of NSCL/P but also in diagnosis and treatment of the patients with NSCL/P.

A Case-control Study of Environmental Risk Factors for Nonsyndromic Cleft of the Lip and/or Palate in Xuzhou, China.

In this study, we sought to determine the association between environmental factors and nonsyndromic cleft of the lip and/or palate (NSCLP) to understand the etiology of the disease. A total of 200 NSCLP cases and 327 controls were recruited at the Maternal and Child Health Hospital of Xuzhou City. We conducted face-to-face interviews with the mothers of both cases and controls. The factors increasing the risk of NSCLP were a positive family history [odds ratio (OR)=56.74], pesticide exposure (OR=8.90), and indoor decoration pollution (OR=4.32). On the other hand, the factors decreasing the risk of NSCLP were a high education level (OR=0.22) and supplementation of folic acid (OR=0.23) and multivitamins (OR=0.16). Positive family history, pesticide exposure, and indoor decoration pollution are associated with the risk of NSCLP. In contrast, high education level and folic acid and multivitamin supplementation are protective factors against NSCLP.

Antagonism effects of cypermethrin on interleukin-6-induced androgen receptor activation.

To identify whether androgen receptor (AR) antagonism by cypermethrin involves interleukin-6 (IL-6)-induced ligand-independent AR signaling, we have developed the AR reporter gene assay. The reporter gene plasmid pMMTV-chloramphenicol transferase (CAT) was transfected into LNCaP cells. IL-6 increased expression of MMTV-CAT significantly (P<0.05). Cypermethrin decreased CAT reporter expression induced by IL-6 (50 ng/ml), and the significant inhibition was detected at 10(-5)M (P<0.05). IL-6 induces ligand-independent activation of AR. Cypermethrin exhibits inhibitory effects on IL-6-induced ligand-independent AR signaling. We provide a novel insight into cypermethrin-mediated antagonism of the IL-6-mediated ligand-independent activation of the AR.

Anti-androgen effects of the pyrethroid pesticide cypermethrin on interactions of androgen receptor with corepressors.

To clarify whether the mechanism of androgen receptor (AR) antagonism of the pyrethroid pesticide cypermethrin associates with the interactions between the AR and corepressors silencing mediator for thyroid hormone receptors (SMRT) and nuclear receptor corepressor (NCoR), we have developed the mammalian two-hybrid assays. The AR N-terminal domain 1-660 amino acid residues were subcloned into the plasmid pVP16 to construct VP16-ARNTD. The C-terminal receptor interaction domains (RIDs) of SMRT and NCoR were used to construct pM-SMRT and pM-NCoR. The constructed vectors pVP16-ARNTD, pM-SMRT or pM-NCoR, the reporter pG5CAT and the control pCMVß were cotranfected into the CV-1 cells. The cells were treated with cypermethrin at the indicated concentrations. The AR N terminus interacted with RIDs of SMRT and NCoR. The interactions between the AR and corepressors SMRT and NCoR were enhanced by cypermethrin, and the significant enhancement was detected at the concentration of 10(-5)M. The mammalian two-hybrid assays demonstrate the utility to detect the interactions of the AR with SMRT and NCoR. Cypermethrin functions as an anti-androgen by enhancing the associations of the AR with SMRT and NCoR. We provide a novel mechanism in anti-androgen action of cypermethrin associated with the recruitment of SMRT and NCoR to AR.