PAQR3 gene expression and its methylation level in colorectal cancer tissues.

The aim of the present study was to investigate the PAQR3 gene expression and its methylation level in colorectal cancer tissues, as well as the association with colorectal cancer clinical data. In total, 54 cases of colorectal cancer tissue samples and normal adjacent tissue samples were collected between June, 2013 and July, 2014. RT-PCR and western blot analysis were used to detect the mRNA and protein levels of PAQR3 in colorectal samples, respectively. MSP was used to detect the methylation level of PAQR3 gene in colorectal samples, which was compared with colorectal data. The results showed that a decreased expression level of PAQR3 mRNA in colorectal cancer tissues and the expression reduction rate was 57.4% (31/54). Similarly, the expression level of PAQR3 protein was reduced in cancer tissues, and the reduction rate was 46.3% (25/54), while the protein expression reduction rate in cancer adjacent tissue was 5.6% (3/54), and the difference was statistically significant (P<0.05). Furthermore, the methylation rates of PAQR3 in cancer tissues and cancer adjacent tissues were 33.3% (18/54) and 5.6% (3/54), respectively. In addition, PAQR3 mRNA and protein levels in colorectal cancer tissues were associated with the differentiation degree, lymphatic metastasis and tumor infiltration depth. The methylation level of PAQR3 was associated with age, differentiated degree, lymphatic metastasis and tumor infiltration depth. In conclusion, the expression of PAQR3 mRNA and protein in colorectal cancer was reduced and methylation of PAQR3 occurred. Although the PAQR3 mRNA and protein levels were not associated with gender, age or the location of tumor, there was an association with differentiation degree, lymphatic metastasis and tumor infiltration depth. In addition, the methylation level of PAQR3 was not correlated with gender or tumor location, but was correlated with age, differentiation degree, lymphatic metastasis and tumor infiltration depth.

Effects of tacrolimus on IFN-γ signaling in keratinocytes: possible mechanisms by which tacrolimus affects IFN-γ-dependent skin inflammation.

Interferon-gamma (IFN-γ) signaling in keratinocytes plays an important role in IFN-γ-induced skin inflammation. A novel tacrolimus topical ointment has shown remarkable efficacy in treating skin inflammation. This study explored the mechanism of tacrolimus-modulated IFN-γ signal transduction in HaCaT keratinocytes and the effects of tacrolimus on IFN-γ-associated cytokine production in HaCaT cells. Tacrolimus down-regulated the recombinant human IFN-γ (rhIFN-γ)-induced expression of IFN-γ receptor α (IFN-γRα). The IFN-γ induced expression of phosphorylated Janus kinase 2 (pJAK2) and phosphorylated signal transducer and activator of transcription-1 (pSTAT-1) was also inhibited by tacrolimus. Tacrolimus up-regulated the IFN-γ-induced expression of suppressor of cytokine signaling-1 (SOCS-1). Tacrolimus was also demonstrated to down-regulate IFN-γ-induced the secretion of chemotactic factor CXCL-8 and the expression of intercellular adhesion molecule-1 and human leucocyte antigen HLA-DR. The findings in this work indicate that the direct effects of tacrolimus on IFN-γ signaling in keratinocytes may contribute to its therapeutic efficacy as a topical ointment in the treatment of IFN-γ-dependent skin inflammation.

Inhibition of the nuclear factor-kappaB signaling pathway by leflunomide or triptolide also inhibits the anthralin-induced inflammatory response but does not affect keratinocyte growth inhibition.

We performed this study to determine the relationship between activation of nuclear factor (NF)-kappaB and inhibition of keratinocyte growth by anthralin, which not only might be useful for a better understanding of the role of NF-kappaB in the pathogenesis of psoriasis, but also indicate whether the inflammatory reaction induced by anthralin is inseparable from its antipsoriatic activity. The involvement of NF-kappaB was assessed using the antipsoriatic drugs leflunomide and triptolide (T0) as effectors, since they can inhibit NF-kappaB activation induced by anthralin. The results showed that the inhibition of keratinocyte growth by anthralin was not related to the activation of NF-kappaB. Using sodium salicylate, a known NF-kappaB inhibitor, further confirmed this conclusion. Thus it might be possible to inhibit the inflammatory response induced by anthralin via repression of NF-kappaB activation. We found that leflunomide or T0 could significantly inhibit the mRNA overexpression of interleukin-8 and intercellular adhesion molecule-1 in keratinocytes induced by anthralin. Taken together, our data indicate that the growth inhibition of anthralin is related to the NF-kappaB-independent signaling pathway, and that leflunomide or T0 could control proinflammatory cytokine expression induced by anthralin via inhibiting the activation of NF-kappaB.