Nuclear factor κB (NF-κB), including RelA, RelB, c-Rel, NF-κB1, and NF-κB2, plays a crucial role in immune response, inflammatory reaction, tumorigenesis, and development of peripheral lymphoid organs and lymphocytes. There are two NF-κB activation pathways: canonical pathway (classical pathway) and noncanonical pathway (alternative pathway). Previous studies focused on the effects of the canonical NF-κB pathway (mainly p50-RelA) in hematological malignancies. Recently, the noncanonical NF-κB pathway (mainly p52-RelB) is gradually taken importance in pathogenesis of hematological malignancies. Understanding the relations of the noncanonical pathway with hematological malignancies would provide a new therapeutic approach for these diseases. This review focuses on the noncanonical NF-κB signaling transduction pathway and its relation to hematologic malignancies.
Hematologic Neoplasms ; metabolism ; Humans ; NF-kappa B ; metabolism ; NF-kappa B p50 Subunit ; metabolism ; NF-kappa B p52 Subunit ; metabolism ; Signal Transduction

<b>OBJECTIVEb>To investigate the function of alternative NF-&kappa;B activity in B-cell chronic lymphocytic leukemia cells (B-CLL).

<b>METHODSb>The mRNA expression of individual NF-&kappa;B subunits in CD5⁺CD19⁺ cells (CLL B-cells) from bone marrow (BM) of 56 patients with B-CLL was analyzed by quantitative RT-PCR. An ELISA-based NF-&kappa;B family transcription factor activity assay was performed to quantify the &kappa;B DNA-binding activity in nuclear extracts from CLL B-cells. Cell death of CLL-B cells was determined by PI staining, RelA and RelB expression at protein level of CLL B-cells by Western blot analyses.

<b>RESULTSb>The expression levels of RelA, p50, RelB and p52 mRNA in CLL B-cells were all higher than that of normal B cells with statistical significance (P<0.05). RelA was activated in almost all the patients detected while RelB activity was induced in part of samples. The average RelA activity in CLL B-cells was increased compared to that in normal B cells while the average RelB activity was similar to that of normal B cells. When cultured in vitro for 24, 48 and 72 hours, the frequencies of cell death of CLL B-cells from RelA⁺/RelB⁻ group were(35.54±4.43)%,(50.92±8.44)%, and(49.24±8.16)%, respectively; that of the RelA⁺/RelB⁺ group were (20.65±2.37)%, (18.17±1.36)%, and (26.55±4.08)%, respectively. When the cells from RelA+/RelB⁻ group were co-cultured with bone marrow stromal cells (hBMSCs), the frequencies of cell death of CLL B-cells were decreased compared to that of the cells cultured alone, while the frequencies of cell death of RelA⁺/RelB⁻ CLL B-cells were higher than that of CLL B-cells from RelA⁺/RelB⁺ group when co-cultured with hBMSCs. RelA and RelB expression in CLL-B cells from the RelA⁺/RelB⁻ group was induced after co-cultured with hBMSCs for 48 h. RelB was reduced in the cytoplasm and increased in the nucleus in CLL-B cells from the RelA+/RelB+ group.

<b>CONCLUSIONb>The alternative NF-&kappa;B was indeed activated and presented heterogeneous in CLL B-cells from BM. Activation of RelB combined with RelA activity could provide the survival advantage to CLL B-cells from BM. Co-culture with hBMSCs could protect CLL-B cells through the induction of RelA and Rel B expressions.

Case-Control Studies ; Cell Nucleus ; metabolism ; Humans ; Leukemia, Lymphocytic, Chronic, B-Cell ; metabolism ; NF-kappa B p50 Subunit ; metabolism ; NF-kappa B p52 Subunit ; metabolism ; Transcription Factor RelA ; metabolism ; Transcription Factor RelB ; metabolism ; Tumor Cells, Cultured

<b>BACKGROUNDb>Currently, no medicine is available that can prevent or treat neural damage associated with optic nerve injury. Minocycline is recently reported to have a neuroprotective function. The aims of this study were to exarmine the neuroprotective effect of minocycline on retinal ganglion cells (RGCs) and determine its underlying mechanisms, using a mouse model of optic nerve crush (ONC).

<b>METHODSb>ONC was performed in the left eye of adult male mice, and the mice were randomly divided into minocycline-treated group and saline-treated control group. The mice without receiving ONC injury were used as positive controls. RGC densities were assessed in retinal whole mounts with immunofluorescence labeling of βIII-tubulin. Transmission electron microscopy was used to detect RGC morphologies, and Western blotting and real-time PCR were applied to investigate the expression of autophagy markers LC3-I, LC3-II, and transcriptional factors nuclear factor-&kappa;B1 (NF-&kappa;B1), NF-&kappa;B2.

<b>RESULTSb>In the early stage after ONC (at Days 4 and 7), the density of RGCs in the minocycline-treated group was higher than that of the saline-treated group. Electron micrographs showed that minocycline prevented nuclei and mitochondria injuries at Day 4. Western blotting analysis demonstrated that the conversion of LC3-I to LC3-II was reduced in the minocycline-treated group at Days 4 and 7, which meant autophagy process was inhibited by minocycline. In addition, the gene expression of NF-&kappa;B2 was upregulated by minocycline at Day 4.

<b>CONCLUSIONb>The neuroprotective effect of minocycline is generated in the early stage after ONC in mice, partly through delaying autophagy process and regulating NF-&kappa;B2 pathway.

Animals ; Autophagy ; drug effects ; Male ; Mice ; Minocycline ; therapeutic use ; NF-kappa B p52 Subunit ; metabolism ; Optic Nerve Injuries ; drug therapy ; metabolism ; Retinal Ganglion Cells ; drug effects ; metabolism

<b>OBJECTIVEb>To explore how NF-&kappa;B family members regulate maspin expression in prostate cancer cells.

<b>METHODSb>The expression of NF-&kappa;B subunits and maspin was detected by Western blot analysis in prostate cancer DU145, PC-3, and LNCaP cell lines. RNA interference was performed to analyze whether RelB- or RelA-deletion affectes cell death as well as the expression of NF-&kappa;B subunits and maspin. The impact of RelB-silencing in DU145 cells was investigated by flow cytometry. The regulation of RelB on maspin expression in the prostate cancer PC-3 cells was also examined via stable transfection of RelB expression plasmid.

<b>RESULTSb>RelA, p50, RelB, and p52 were constitutively expressed in androgen-independent prostate cancer DU145 and PC-3 cells, while RelB had the highest expression in DU145 cells. Low expression of maspin was detected in LNCaP and DU145 cells, but elevated expression in PC-3 cells. RelB-silencing in DU145 cells by siRNA interference upregulated the endogenous expression of maspin and induced cell apoptosis (13.3±4.2)%. Overexpression of RelB in PC-3 cells inhibited the endogenous expression of maspin. RelA-silecing had no significant influence on the endogenous expression of maspin.

<b>CONCLUSIONSb>The classical and alternative NF-&kappa;B activitions are sustained in androgen-independent prostate cancer cell lines. The expressions of RelB and maspin are inversely correlated in these cancer cells. The expression of RelB negatively regulates the endogenous expression of maspin, then interferes the cell survival. RelA is not involved in the regulation of maspin expression.

Apoptosis ; Cell Line, Tumor ; Gene Silencing ; Humans ; Male ; NF-kappa B ; genetics ; metabolism ; NF-kappa B p50 Subunit ; genetics ; metabolism ; NF-kappa B p52 Subunit ; genetics ; metabolism ; Prostatic Neoplasms ; genetics ; metabolism ; pathology ; RNA, Small Interfering ; genetics ; Serpins ; metabolism ; Transcription Factor RelA ; genetics ; metabolism ; Transcription Factor RelB ; genetics ; metabolism ; Transfection