There is growing evidence for a connection between inflammation and tumor development, and the nuclear factor kappa B (NF-B), a proinflammatory transcription factor, is hypothesized to promote tumorigenesis. Although the genetic evidence for the hypothesis has been lacking, recent papers have lent credence to this hypothesis. It has been reported that constitutive NF-B activation in inflammatory bowel diseases (

Background & Aims Constitutive activation of NF-κB and STAT3 pathways in human colorectal cancers links inflammation to CRC development and progression. However, the underlying mechanisms remain to be elucidated. Here we investigated the roles of miR-221 and miR-222 in regulating both NF-κB and STAT3 activities and colorectal tumorigenesis. Methods miR-221/222 mimics and their inhibitors/sponges were transiently or stably transfected into cells. Dual luciferase reporter assays were utilized to examine the activation of both NF-κB and STAT3 signaling, as well as the regulation of miR-221/222. Quantitative PCR and immunoblot analysis were employed to examine the mRNA and protein expression. MTT assay, flow cytometric analysis and xenotransplant of tumor cells were performed to investigate the CRC cell growth in vitro and in vivo. Results miR-221 and miR-222 positively regulate both NF-κB and STAT3 activities, which in return induce miR-221/222 expression, creating a positive feedback loop in human CRCs. miR-221/222 directly bind to the coding region of RelA, leading to increased RelA mRNA stability. In addition, miR-221/222 reduce ubiquitination of RelA and STAT3 proteins by directly targeting the 3′ UTR of PDLIM2, an E3 ligase for both RelA and STAT3. We demonstrate that disruption of the positive feedback loop suppresses human CRC cell growth in vitro and in vivo. The expression of miR-221/222 correlates with the expression of RelA, STAT3 and PDLIM2 in human CRC clinical samples. Conclusions Our findings define a novel miR-221/222 mediated mechanism underlying constitutive activation of NF-κB and STAT3 pathways in human CRCs and provide a promising therapeutic target for human CRCs.

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HE4 is a potential biomarker of kidney injury in acute and chronic renal dysfunction. Importantly, clinicians should be aware of this when using HE4 to diagnose ovarian cancer.

Progressive renal fibrosis in chronic kidney disease (CKD) greatly contributes to end-stage renal failure and is associated with high mortality. The identification of renal fibrosis biomarkers for the diagnosis and the monitoring of disease progression in CKD is urgently needed. Whole-transcriptomic analysis of renal tissues in a unilateral ureteral obstruction (UUO) mouse model revealed that the mRNA level of Bcl-3, an atypical member of the IκB family, was induced 6.3-fold 2 days after UUO. Compared with renal tissues in sham-operated mice, increases in Bcl-3 mRNA and protein in the renal tissues in the UUO model were accompanied with increases in other markers of renal fibrosis, including human epididymis protein 4 (HE4), a recently identified biomarker of renal fibrosis. Immunohistochemical analysis revealed that both Bcl-3 and HE4 were located in the plasma of renal tubule cells. Serum protein levels of Bcl-3 and HE4 rose with the development of renal fibrosis in UUO mouse model. We found that the serum protein levels of both HE4 and Bcl-3 were elevated in CKD patients compared with healthy controls. Moreover, a significant positive correlation between Bcl-3 and HE4 (r = 0.939, p < 0.0001) was observed in CKD patients. These data suggest that Bcl-3 can serve as a novel valuable biomarker of renal fibrosis in CKD.