Heat Shock Transcription Factor 2 Is Significantly Involved in Neurodegenerative Diseases, Inflammatory Bowel Disease, Cancer, Male Infertility, and Fetal Alcohol Spectrum Disorder: The Novel Mechanisms of Several Severe Diseases.

HSF (heat shock transcription factor or heat shock factor) was discovered as a transcription factor indispensable for heat shock response. Although four classical HSFs were discovered in mammals and two major HSFs, HSF1 and HSF2, were cloned in the same year of 1991, only HSF1 was intensively studied because HSF1 can give rise to heat shock response through the induction of various HSPs' expression. On the other hand, HSF2 was not well studied for some time, which was probably due to an underestimate of HSF2 itself. Since the beginning of the 21st century, HSF2 research has progressed and many biologically significant functions of HSF2 have been revealed. For example, the roles of HSF2 in nervous system protection, inflammation, maintenance of mitosis and meiosis, and cancer cell survival and death have been gradually unveiled. However, we feel that the fact HSF2 has a relationship with various factors is not yet widely recognized; therefore, the biological significance of HSF2 has been underestimated. We strongly hope to widely communicate the significance of HSF2 to researchers and readers in broad research fields through this review. In addition, we also hope that many readers will have great interest in the molecular mechanism in which HSF2 acts as an active transcription factor and gene bookmarking mechanism of HSF2 during cell cycle progression, as is summarized in this review.

Deep Ultraviolet Light-Emitting Diode Light Therapy for Fusobacterium nucleatum.

BACKGROUND: Fusobacterium nucleatum, which is associated with periodontitis and gingivitis, has been detected in colorectal cancer (CRC). METHODS: We evaluated the bactericidal effect of deep ultraviolet (DUV) light-emitting diode (LED) light therapy on F. nucleatum both qualitatively and quantitatively. Two DUV-LEDs with peak wavelengths of 265 and 280-nm were used. DNA damage to F. nucleatum was evaluated by the production of cyclobutane pyrimidine dimers (CPD) and pyrimidine (6-4) pyrimidone photoproducts (6-4PP). RESULTS: DUV-LEDs showed a bactericidal effect on F. nucleatum. No colony growth was observed after 3 min of either 265 nm or 280 nm DUV-LED irradiation. The survival rates of F. nucleatum under 265 nm DUV-LED light irradiation dropped to 0.0014% for 10 s and to 0% for 20 s irradiation. Similarly, the survival rate of F. nucleatum under 280 nm DUV-LED light irradiation dropped to 0.00044% for 10 s and 0% for 20 s irradiation. The irradiance at the distance of 35 mm from the DUV-LED was 0.265 mW/cm2 for the 265 nm LED and 0.415 mW/cm2 for the 280 nm LED. Thus, the radiant energy for lethality was 5.3 mJ/cm2 for the 265 nm LED and 8.3 mJ/cm2 for the 280 nm LED. Amounts of CPD and 6-4PP in F. nucleatum irradiated with 265 nm DUV-LED light were 6.548 ng/µg and 1.333 ng/µg, respectively. CONCLUSIONS: DUV-LED light exerted a bactericidal effect on F. nucleatum by causing the formation of pyrimidine dimers indicative of DNA damage. Thus, DUV-LED light therapy may have the potential to prevent CRC.

CD56 expression in human myeloma cells derived from the neurogenic gene expression: possible role of the SRY-HMG box gene, SOX4.

CD56 is frequently detected on primary myeloma cells from more than 80% patients with overt myeloma. In order to clarify the possible mechanisms of CD56 expression in human myeloma, we underwent screening for potential targets by microarray analysis, where the CD56(+) myeloma cell lines showed markedly increased expressions of transcription factors involved in the neuronal cell lineage compared to the CD56(-) myeloma cell lines. Here, we show that among the SOX family of transcription factors, SOX4 was highly up-regulated and SOX1 was down-regulated in the CD56(+) myeloma cell lines as well as in primary myeloma cases as confirmed by the RT-PCR. ChIP analysis of the CD56 promoter region showed specific bindings of SOX4 in the CD56(+) and SOX1 in the CD56(-) myeloma cell lines, respectively. shRNA against SOX1 failed to induce CD56 expression in CD56(-) myeloma cell line, U266. On the contrary, over-expression of SOX4 in the CD56(-) myeloma cell line could induce the CD56 expression. Silencing of SOX4 by shRNA transfection down-regulated CD56 expression and induced apoptosis to CD56(+) human myeloma cell line, AMO1. Thus, induction of SOX4 gene expression might be responsible for the CD56 expression in human myeloma cells.

Constitutively lower expressions of CD54 on primary myeloma cells and their different localizations in bone marrow.

To evaluate nuclear factor-kappaB (NF-kappaB) activity in primary myeloma cells from myeloma patients, we confirmed that the expression levels of CD54 showed a good correlation with the levels of DNA binding activity for NF-kappaB in human myeloma cell lines, and thus analyzed the expression levels of CD54 on CD38(++) plasma cell fractions as one of NF-kappaB activity. Primary myeloma cells unexpectedly showed constitutively lower expressions of CD54 than normal bone marrow (BM) plasma cells. Furthermore, the expression levels of CD54 on these plasma cells showed a significant correlation with the plasma levels of CXCL12 stromal cell-derived factor-1alpha (SDF-1alpha) in their BM aspirates, and the expressions of CXCR4, the receptor for CXCL12, decreased on primary myeloma cells compared with normal BM plasma cells. It was also confirmed that the addition of CXCL12 to the in vitro culture significantly induced the up-regulation of CD54 expression in primary myeloma cells. In addition, myeloma cells with lower expressions of CD54 were more unstable in the in vitro culture, resulting in a marked reduction of the viable cell number. In the immunohistochemical analysis of BM aspirates, myeloma cells with lower CD54 expression resided in the perivascular regions. Therefore, these data suggest that primary myeloma cells exhibit constitutively lower CD54 that might be partially regulated by CXCL12, and their localizations in the BM may be associated with the expression levels of CD54.

IL-6-induced activation of MYC is responsible for the down-regulation of CD33 expression in CD33+ myeloma cells.

Human myeloma cells from about 10% of cases with multiple myeloma expressed CD33 and had monocytoid morphology with convoluted nuclei, and all these patients had no increase in serum CRP values. In CD33(+) myeloma cells as well as myeloma cell lines, CD33 expression levels were correlated with the increased expression levels of CEBPA (C/EBPalpha). This correlation was confirmed by the finding that transfection with the CEBPA gene induced CD33 expression in a CD33(-) myeloma cell line. As suggested by the lack of an increase in serum CRP values in CD33(+) myelomas, IL-6 down-regulated the expression of CD33 in CD33(+) myeloma cell lines along with the down-regulation of CEBPA gene expression. Cucurbitacin I (STAT3 inhibitor), but not U0126 (MAPK inhibitor), could abolish the effect of IL-6. Furthermore, IL-6 up-regulated the expression of MYC via STAT3 phosphorylation and MYC bound to the promoter region of the CEBPA gene followed by the down-regulation of CEBPA expression. It was confirmed that introduction of shRNA for MYC into a CD33(+) myeloma cell line blocked the IL-6-induced down-regulation of CD33 and CEBPA expression. Therefore, these results indicate that IL-6 can reverse the expression level of CD33 by up-regulating MYC followed by the down-regulation of CEBPA expression.

Galectin-1 supports the survival of CD45RA(-) primary myeloma cells in vitro.

The survival and proliferation of human myeloma cells are considered to be heavily dependent on the microenvironment of bone marrow (BM). This study confirmed that galectin-1 (Gal-1) and SDF-1alpha were produced by bone marrow mononuclear cells of myeloma patients. The addition of Gal-1 and SDF-1alpha to a serum-free synthetic medium, maintained the viability of primary myeloma cells for 2 weeks similar to that before culture. While Gal-1 reduced the viable cell number in CD45RA(+) B cell lines, it maintained the viability of CD45(-) U266 and CD45RA(-)RO(+) ILKM3 myeloma cell lines in the synthetic medium. This was confirmed with the transfection of the PTPRC (CD45) RA, -RB, or -RO gene into CD45(-) U266 cells. The combination of Gal-1 and SDF-1alpha significantly induced phosphorylation of Akt and IkB, while the phosphorylation of ERK1/2 was significantly reduced in CD45RA(+) U266 and Raji cells but not CD45(-) or CD45RA(-) U266 cells. Furthermore, we confirmed that Gal-1 bound to CD45RA in CD45RA(+) Raji cells, and also physically interacted with beta1-integrin by immunoprecipitation followed by Western blotting and confocal microscopy. The results suggest that Gal-1 has two different actions depending on its binding partner, and supports the survival of CD45RA(-) myeloma cells.

[Molecular mechanism of oncogenesis and progression in human myeloma].

Cellular biology of primary myeloma cells from myeloma patients, has been rapidly developing by using DNA analysis, gene expression profiling (GEP) and surface marker analysis. These studies reveal that human myeloma cells specifically lose the expression of B cell master gene, PAX-5, and express multi-lineage markers, and XBP-1 transgenic mice showed the late onset of human myeloma-like monoclonal plasmacytosis in the bone marrow of aged mice. GEP reveals that primary myeloma cells are subdivided into 7 groups: among these subgroups, PR (proliferation) group predicts poor prognosis. With regard to molecular mechanism of myeloma oncogenesis, the importance of primary IgH translocation followed by the second IgH translocation is proposed, but it is also noted that human myeloma cells show the marked heterogeneity.

Induction of multilineage markers in human myeloma cells and their down-regulation by interleukin 6.

Human primary myeloma cells are well known to be heterogeneous with regard to morphology and surface phenotype. We confirmed the heterogeneous expression of such multilineage markers as CD33, CD7, CD56, CD4, and CD86 in primary myeloma cells from 20 patients with multiple myeloma and in 8 human myeloma cell lines. CD33 expression in the Liu01 cell line, a subclone of U266 cells, and in vitamin D3-treated ILKM3 cells, correlated with a monocytoid morphology featuring convoluted nuclei and with increased C/EBPalpha expression. CD56+ myeloma cells from some myeloma patients and the CD56+ (but not the CD56-) myeloma cell lines expressed neuronal cell markers, such as neuron-specific enolase and beta-tubulin III. CD7 expression in Liu01 cells and forskolin-stimulated U266 cells coincided with the presence of large cytoplasmic granules, and these cells featured increased expression of perforin messenger RNA and significant natural killer cell activity. Interleukin 6 (IL-6), a growth factor for myeloma cells, down-regulated CD33, CD7, or CD56 expression in primary myeloma cells, as well as in Liu01 cells. Therefore, these data suggest that human myeloma cells are capable of inducing the expression of multilineage markers and that IL-6 can down-regulate such expression.

Heterogeneous expression of CD32 and CD32-mediated growth suppression in human myeloma cells.

BACKGROUND AND OBJECTIVES: An increased level of serum M-protein IgG may affect the growth or survival of myeloma cells through the Fcgamma inverted exclamation mark receptor (FcgammaR) in human myelomas. We examined the expression of FcgammaR (CD32, CD16 and CD64) and compared the effect of anti-CD32 antibody on the viability of myeloma cells to that on the viability of normal plasma cells. DESIGN AND METHODS: Surface antigen and gene expressions were examined by flow cytometry and reverse transcription polymerase chain reaction, respectively. We examined the effect of anti-CD32 antibody on the viability of CD19- myeloma cells (including immature and mature myeloma cells) and CD19+ normal plasma cells. In order to confirm the involvement of CD19 in the anti-CD32-mediated growth suppression, we used CD19 transfectants of myeloma, B-cell and erythroleukemia cell lines that we have already established. RESULTS: CD32 was significantly expressed on primary myeloma cells, but immature, MPC-1- myeloma cells expressed CD32 more weakly than mature, MPC-1+ cells. Treatment with anti-CD32 antibody decreased the viability of normal plasma cells (CD38++ CD19+) more than that of myeloma cells (CD38++ CD19-); CD32-mediated growth suppression was greater in mature MPC-1+ cells than in immature MPC-1- cells. The introduction of CD19 into CD19- cell lines significantly increased the sensitivity of the cells to treatment with anti-CD32 antibody as well as addition of IgG complex; furthermore, increased phosphorylation of CD32 and SHIP was detected in CD19-transfected cell lines. INTERPRETATION AND CONCLUSIONS: Myeloma cells lacking CD19 expression are less sensitive to CD32-mediated growth suppression than are CD19+ normal plasma cells.

An increase in MPC-1- and MPC-1-CD45+ immature myeloma cells in the progressive states of bone marrow plasmacytosis: the revised phenotypic classification of monoclonal marrow plasmacytosis (MOMP-2005).

The heterogeneity of bone marrow plasmacytosis is clearly analyzed by multicolor staining with anti-CD38 antibody. To date, at least 5 subpopulations of plasma cells have been identified in the bone marrow of multiple myeloma (MM) patients with regard to the expression of MPC-1, CD49e (VLA-5), and CD45: MPC-1(-)CD49e(-)CD45(+) proliferative immature cells, MPC-1(-)CD49e(-)CD45(-) immature myeloma cells, MPC-1(+)CD49e(-)CD45(-) and MPC-1(+)CD49e(-)CD45(+) intermediate myeloma cells, and MPC-1(+)CD49e(+)CD45(+) mature myeloma cells. We performed phenotypic analyses in 75 cases of monoclonal bone marrow plasmacytosis, including 46 cases of MM and 29 cases of monoclonal gammopathy of undetermined significance (MGUS). In 31 cases of progressive MM disease, MPC-1(-) immature and MPC-1(-)CD45(+) proliferative immature myeloma cells were significantly increased up to >25% and >10%, respectively, of the plasma cell fractions (CD38(++) cells), whereas there were no increases in MPC-1(-) or MPC-1(-)CD45(+) proliferative immature myeloma cells in 15 cases of stable disease. Interestingly, the proportions of MPC-1(-) and MPC-1(-)CD45(+) immature monoclonal plasma cells also increased in the 7 progressive cases of MGUS. Finally, we present the revised (2005) phenotypic classification of monoclonal marrow plasmacytosis (MOMP-2005).

IL-6-induced Bcl6 variant 2 supports IL-6-dependent myeloma cell proliferation and survival through STAT3.

IL-6 is a growth and survival factor for myeloma cells, although the mechanism by which it induces myeloma cell proliferation through gene expression is largely unknown. Microarray analysis showed that some B-cell lymphoma-associated oncogenes such as Bcl6, which is absent in normal plasma cells, were upregulated by IL-6 in IL-6-dependent myeloma cell lines. We found that Bcl6 variant 2 was upregulated by STAT3. ChIP assay and EMSA showed that STAT3 bound to the upstream region of variant 2 DNA. Expression of p53, a direct target gene of Bcl6, was downregulated in the IL-6-stimulated cells, and this process was impaired by an HDAC inhibitor. Bcl6 was knocked down by introducing small hairpin RNA, resulting in decreased proliferation and increased sensitivity to a DNA damaging agent. Thus, STAT3-inducible Bcl6 variant 2 appears to generate an important IL-6 signal that supports proliferation and survival of IL-6-dependent myeloma cells.

Accelerated proliferation of myeloma cells by interleukin-6 cooperating with fibroblast growth factor receptor 3-mediated signals.

Interleukin-6 (IL-6) is a cytokine that regulates the proliferation of some tumor cells including multiple myeloma (MM). Ectopic expression of fibroblast growth factor receptor 3 (FGFR 3) associated with the chromosomal translocation, t(4;14)(p16.3;q32), is frequently found in MM, and therefore, has been implicated in the neoplastic transformation of this disease. Here, we show that IL-6 together with FGF enhanced proliferation of a myeloma cell line, KMS-11 carrying t(4;14)(p16.3;q32) and the FGFR 3-transfected U 266 myeloma cell line which ectopically expressed FGFR 3 but responded to neither IL-6 nor FGF alone. In KMS-11, IL-6 activated signal transducer and activator of transcription 3 (STAT 3) while FGF activated extracellular signal-regulated kinase 1/2 (ERK 1/2) and phosphatidylinositol (PI)-3 kinase. As both MEK inhibitors and a PI 3-kinase inhibitor abolished the effect of IL-6 and FGF, the activation of both the ERK 1/2 and PI 3-kinase signaling cascades is essential for the proliferation of KMS-11 enhanced by IL-6 and FGF. Furthermore, the FGF-induced activation of ERK 1/2 contributed to the serine phosphorylation of STAT 3, suggesting that the signaling crosstalk between the cytokine receptor, IL-6 receptor alpha/gp 130 and the growth factor receptor tyrosine kinase, FGFR 3. These results indicate that FGFR 3 plays a crucial role in the accelerated proliferation of MM carrying t(4;14)(p16.3;q32).

Dehydroepiandrosterone can inhibit the proliferation of myeloma cells and the interleukin-6 production of bone marrow mononuclear cells from patients with myeloma.

The serum levels of an adrenal sex hormone, dehydroepiandrosterone sulfate (DHEA-S), are significantly more decreased in human myelomas compared with the reduction brought by physiologic decline with age. In order to clarify the effect of DHEA on myeloma cells, we investigated whether DHEA and DHEA-S could inhibit interleukin-6 (IL-6) production of bone marrow mononuclear cells and the proliferation of myeloma cells from patients with myeloma. DHEA-S and DHEA suppressed IL-6 production from a bone marrow stromal cell line, KM-102, as well as in bone marrow mononuclear cells from patients with myeloma. Furthermore, DHEA inhibited in vitro growth of the U-266 cell line and primary myeloma cells from the patients, as well as the in vivo growth of U-266 cells implanted i.p. in severe combined immunodeficiency-hIL6 transgenic mice. DHEA up-regulated the expression of peroxisome proliferator-activated receptor (PPAR), PPAR beta, but not PPARgamma or PPARalpha, and the expression of IkappaBalpha gene in myeloma cells and bone marrow stromal cells, which could explain the suppressive effect of DHEA on IL-6 production through the down-regulation of NF-kappaB activity. Therefore, these data revealed that DHEA-S, as well as DHEA, had a direct effect on myeloma and bone marrow stromal cells to inhibit their proliferation and IL-6 production, respectively.

A rapid translocation of CD45RO but not CD45RA to lipid rafts in IL-6-induced proliferation in myeloma.

CD45, a receptor-type tyrosine phosphatase, is required for interleukin-6 (IL-6)-induced proliferation in human myeloma cells, which express the shortest isoform, CD45RO, but not the longest isoform, CD45RA. Here, we showed that IL-6 induced the translocation of CD45 to lipid rafts in an isoform-dependent manner. In myeloma cells, CD45RO was translocated to lipid rafts more rapidly than CD45RB, but exogenously expressed CD45RA was not translocated. When an IL-6Ralpha-transfected B-cell line was stimulated with IL-6, CD45RA was not translocated, although CD45RB was. We further confirmed that the translocated CD45 bound to IL-6Ralpha, Lyn, and flotillin-2, and this was followed by the dephosphorylation of the negative regulatory Tyr507 of Lyn. CD45 also bound to phosphoprotein associated with glycosphingolipid-enriched microdomains (PAGs), which were subsequently dephosphorylated, resulting in the release of C-terminal src kinase (Csk) from lipid rafts. Therefore, these results indicate that a rapid translocation of CD45RO to lipid rafts may be responsible for IL-6-induced proliferation, and that the change from CD45RA to CD45RO confers the ability to respond to IL-6 in human myeloma cells.

Baicalein, a component of Scutellaria radix from Huang-Lian-Jie-Du-Tang (HLJDT), leads to suppression of proliferation and induction of apoptosis in human myeloma cells.

In the search for a more effective adjuvant therapy to treat multiple myeloma (MM), we investigated the effects of the traditional Chinese herbal medicines Huang-Lian-Jie-Du-Tang (HLJDT), Gui-Zhi-Fu-Ling-Wan (GZFLW), and Huang-Lian-Tang (HLT) on the proliferation and apoptosis of myeloma cells. HLJDT inhibited the proliferation of myeloma cell lines and the survival of primary myeloma cells, especially MPC-1- immature myeloma cells, and induced apoptosis in myeloma cell lines via a mitochondria-mediated pathway by reducing mitochondrial membrane potential and activating caspase-9 and caspase-3. Further experiments confirmed that Scutellaria radix was responsible for the suppressive effect of HLJDT on myeloma cell proliferation, and the baicalein in Scutellaria radix showed strong growth inhibition and induction of apoptosis in comparison with baicalin or wogonin. Baicalein as well as baicalin suppressed the survival in vitro of MPC-1- immature myeloma cells rather than MPC-1+ myeloma cells from myeloma patients. Baicalein inhibited the phosphorylation of IkB-alpha, which was followed by decreased expression of the IL-6 and XIAP genes and activation of caspase-9 and caspase-3. Therefore, HLJDT and Scutellaria radix have an antiproliferative effect on myeloma cells, especially MPC-1- immature myeloma cells, and baicalein may be responsible for the suppressive effect of Scutellaria radix by blocking IkB-alpha degradation.

Receptor synergy of interleukin-6 (IL-6) and insulin-like growth factor-I in myeloma cells that highly express IL-6 receptor alpha [corrected].

Interleukin-6 (IL-6) is a growth and antiapoptotic factor for human myeloma cells. The autocrine loop and increased expression of the growth factor receptors have been postulated as the mechanisms of tumorigenesis. Here we show that IL-6 stimulation induced the phosphorylation of insulin-like growth factor-I (IGF-I) receptors in a human myeloma cell line, NOP2, highly expressing IL-6 receptor alpha (IL-6R alpha) and in the IL-6R alpha-transfected U266 cell line. IL-6-dependent complex formation of IL-6R alpha with IGF-I receptor beta was found in NOP2 where IL-6R alpha colocalized with IGF-I receptors at lipid rafts. Moreover, the IL-6-induced phosphorylation of IGF-I receptor beta was not blocked by a Janus kinase 2 (Jak2) inhibitor. In addition to the activation of the signal transducer and activator of transcription 3 and extracellular signal-regulated kinase 1/2, IL-6 stimulation led to the activation of Akt, presumably following the phosphorylation of IGF-I receptors. Thus, our results suggest that in NOP2, IL-6R alpha and IGF-I receptors exist on the plasma membrane in close proximity, facilitating the efficient assembly of 2 receptors in response to IL-6. The synergistic effects of highly expressed IL-6R alpha on IGF-I receptor-mediated signals provide a novel insight into the Jak-independent IL-6 signaling mechanism of receptor cross-talk in human myeloma cells.

The regulatory mechanism of IL-6-dependent proliferation of human myeloma cells.

Multiple myeloma (MM) is a malignant tumor of plasma cells in the bone marrow. Interleukin 6 (IL-6) is an indispensable growth factor for myeloma cells. The heterogeneity of myeloma cells are the characteristics of MM, categorized into five sub-populations, two immature cells, MPC-1

Interleukin-6, CD45 and the src-kinases in myeloma cell proliferation.

Multiple myeloma (MM) is a proliferative disorder of monoclonal plasma cells which accumulate in human bone marrow, and myeloma cells proliferate in response to a cytokine, interleukin-6 (IL-6). We recently found that MPC-1- CD49e- immature myeloma cells expressing CD45 form a proliferating population in MM. IL-6 activates at least two intracellular pathways including signal transducer and activator of transcription 3 (STAT3) and extracellular signal-regulated kinase 1/2 (ERK1/2) following the activation of Janus kinases (JAKs) via its receptor complexes composed of the IL-6 receptor alpha chain and gp130. Although the roles of CD45 have been extensively studied for antigen receptors in B and T cells, its physiological consequences in other hematopoietic cells remain largely unknown. Myeloma cells expressing CD45 antigens which contain the activation of src family protein-tyrosine kinases (PTKs) independent of IL-6 stimulation proliferate in response to IL-6, whereas the proliferation of CD45- cells which lack a considerable activity of the src family PTKs is not promoted by IL-6. The STAT3 and ERK1/2 pathways are similarly activated by IL-6 in both cells either expressing or not expressing CD45. In this review, we argue a novel mechanism of proliferation of myeloma cells, in that the activation of both STAT3 and ERK1/2 is not sufficient for IL-6-induced proliferation which further requires IL-6-independent activation of the src family kinases associated with CD45 phosphatase. We propose that the cellular context, such as CD45 expression and src family kinase activation, is crucial for myeloma cells to proliferate in response to IL-6.