Antineoplastic chemotherapeutic agents may indirectly activate dendritic cells (DCs) by inducing the release of “danger” signals from dying tumor cells. Whereas the direct cytotoxic or inhibitory effect of conventional chemotherapy on DCs has been reported, modulation of DC function by chemotherapeutic agents in low noncytotoxic concentrations has not yet been investigated. We have tested the effects of different classes of antineoplastic chemotherapeutic agents used in low noncytotoxic concentrations on the Ag-presenting function of DCs. We revealed that paclitaxel, doxorubicin, mitomycin C, and methotrexate up-regulated the ability of DCs to present Ags to Ag-specific T cells. Stimulation of DC function was associated with the up-regulation of expression of Ag-processing machinery components and costimulatory molecules on DCs, as well as increased IL-12p70 expression. However, the ability of DCs treated with paclitaxel, methotrexate, doxorubicin, and vinblastine to increase Ag presentation to Ag-specific T cells was abolished in DCs generated from IL-12 knockout mice, indicating that up-regulation of Ag presentation by DCs is IL-12-dependent and mediated by the autocrine or paracrine mechanisms. At the same time, IL-12 knockout and wild-type DCs demonstrated similar capacity to up-regulate OVA presentation after their pretreatment with low concentrations of mitomycin C and vincristine, suggesting that these agents do not utilize IL-12-mediated pathways in DCs for stimulating Ag presentation. These findings reveal a new mechanism of immunopotentiating activity of chemotherapeutic agents—a direct immunostimulatory effect on DCs (chemomodulation)—and thus provide a strong rationale for further assessment of low-dose chemotherapy given with DC vaccines for cancer treatment.

Low estrogen levels undoubtedly underlie menopausal bone thinning. However, rapid and profuse bone loss begins 3 y before the last menstrual period, when serum estrogen is relatively normal. We have shown that the pituitary hormone FSH, the levels of which are high during late perimenopause, directly stimulates bone resorption by osteoclasts. Here, we generated and characterized a polyclonal antibody to a 13-amino-acid-long peptide sequence within the receptor-binding domain of the FSH β-subunit. We show that the FSH antibody binds FSH specifically and blocks its action on osteoclast formation in vitro. When injected into ovariectomized mice, the FSH antibody attenuates bone loss significantly not only by inhibiting bone resorption, but also by stimulating bone formation, a yet uncharacterized action of FSH that we report herein. Mesenchymal cells isolated from mice treated with the FSH antibody show greater osteoblast precursor colony counts, similarly to mesenchymal cells isolated from FSH receptor (FSHR) −/− mice. This suggests that FSH negatively regulates osteoblast number. We confirm that this action is mediated by signaling-efficient FSHRs present on mesenchymal stem cells. Overall, the data prompt the future development of an FSH-blocking agent as a means of uncoupling bone formation and bone resorption to a therapeutic advantage in humans.osteoporosis | sex steroids | skeletal anabolic | gonadotropin W omen lose over 3% of bone mass during late perimenopause at which time estrogen levels remain relatively unperturbed (1, 2). This bone loss begins 3 y before the last menstrual period (3), and arises from a profound elevation in bone resorption, which is not compensated by parallel increases in bone formation (4). Inhibiting bone resorption during this period with an anticatabolic agent, such as a bisphosphonate, selective estrogen receptor modulator, or estrogen itself, attenuates bone loss (5). However, estrogen use can be associated with increased breast cancer risk and designer estrogens have undesirable side effects. Further, growing concerns regarding oversuppression of bone turnover by bisphosphonates limit their use as early as perimenopause (5). The relatively small armamentarium for osteoporosis therapies, particularly for early and rapidly progressing bone loss, makes the advent of newer preventative strategies very desirable.A close examination of hormonal changes in women during late perimenopause shows that, whereas estrogen levels remain unperturbed, FSH levels have begun to rise, likely to compensate for failing ovaries (3). Strong correlations between rising serum FSH levels and bone loss have been documented, particularly in the Study of Women's Health Across Nations (SWAN) (2, 6). Furthermore, amenorrheic women with high FSH levels >35 IU/L display greater decrements in bone density than those with a mean FSH of ∼8 IU/L (7). Likewise, women having activating FSH receptor (FSHR) polymorphisms have a low bone mass and high bone turnover (8). Together, these findings suggest that a rising ...

Anthocyanins are a group of naturally occurring phenolic compounds widely available in fruits and vegetables in human diets. They have broad biological activities including antimutagenesis and anticarcinogenesis, which are generally attributed to their antioxidant activities. We studied the effects and the mechanisms of the most common type of anthocyanins, cyanidin-3-rutinoside, in several leukemia and lymphoma cell lines. We found that cyanidin-3-rutinoside extracted and purified from the black raspberry cultivar Jewel induced apoptosis in HL-60 cells in a dose-and time-dependent manner. Paradoxically, this compound induced the accumulation of peroxides, which are involved in the induction of apoptosis in HL-60 cells. In addition, cyanidin-3-rutinoside treatment resulted in reactive oxygen species (ROS)-dependent activation of p38 MAPK and JNK, which contributed to cell death by activating the mitochondrial pathway mediated by Bim. Down-regulation of Bim or overexpression of Bcl-2 or Bcl-x L considerably blocked apoptosis. Notably, cyanidin-3-rutinoside treatment did not lead to increased ROS accumulation in normal human peripheral blood mononuclear cells and had no cytotoxic effects on these cells. These results indicate that cyanidin-3-rutinoside has the potential to be used in leukemia therapy with the advantages of being widely available and selective against tumors.

Breast and kidney-expressed chemokine (BRAK) CXCL14 is a new CXC chemokine with unknown function and receptor selectivity. The majority of head and neck squamous cell carcinoma (HNSCC) and some cervical squamous cell carcinoma do not express CXCL14 mRNA, as opposed to constitutive expression by normal oral squamous epithelium. In this study, we demonstrate that the loss of CXCL14 in HNSCC cells and at HNSCC primary tumor sites was correlated with low or no attraction of dendritic cell (DC) in vitro, and decreased infiltration of HNSCC mass by DC at the tumor site in vivo. Next, we found that recombinant human CXCL14 and CXCL14-positive HNSCC cell lines induced DC attraction in vitro, whereas CXCL14-negative HNSCC cells did not chemoattract DC. Transduction of CXCL14-negative HNSCC cell lines with the human CXCL14 gene resulted in stimulation of DC attraction in vitro and increased tumor infiltration by DC in vivo in chimeric animal models. Furthermore, evaluating the biologic effect of CXCL14 on DC, we demonstrated that the addition of recombinant human CXCL14 to DC cultures resulted in up-regulation of the expression of DC maturation markers, as well as enhanced proliferation of allogeneic T cells in MLR. Activation of DC with recombinant human CXCL14 was accompanied by up-regulation of NF-κB activity. These data suggest that CXCL14 is a potent chemoattractant and activator of DC and might be involved in DC homing in vivo.

We report that adrenocorticotropic hormone (ACTH) protects against osteonecrosis of the femoral head induced by depot methylprednisolone acetate (depomedrol). This therapeutic response likely arises from enhanced osteoblastic support and the stimulation of VEGF by ACTH; the latter is largely responsible for maintaining the fine vascular network that surrounds highly remodeling bone. We suggest examining the efficacy of ACTH in preventing human osteonecrosis, a devastating complication of glucocorticoid therapy.osteoporosis | osteoclast | osteoblast T he use of glucocorticoids for medical conditions as diverse as asthma, ulcerative colitis, kidney diseases, and rheumatologic disorders causes not only a variety of metabolic and medical complications, including diabetes and osteoporosis, but also a painful debilitating condition, osteonecrosis, usually affecting the femoral head (1). Osteonecrosis almost invariably requires surgical debridement of dead bone and contributes to approximately 10% of the more than 500,000 hip replacements annually in the United States (2). In addition, 30-50% patients on long-term glucocorticoids sustain a hip fracture with a 2-to 2.5-fold increased risk (3).Osteocyte apoptosis is thought to be the key determinant of glucocorticoid-induced cortical bone loss (4). Reduced osteoblast function manifesting in attenuated bone formation has also been documented in trabecular bone in rodents and humans (5). In contrast to glucocorticoid-induced osteoporosis, the pathogenesis of glucocorticoid-induced osteonecrosis is unclear (6). It resembles the osteonecrosis caused by traumatic damage to the artery that supplies the femoral head, hence the name, avascular necrosis (3), but the necrosis actually begins as regional trabecular death (6), likely from osteoblast and osteocyte apoptosis. However, there is strong evidence for an ischemic component. For example, studies using a rat model of Legg-Calve-Perthe's disease suggest that the intracortical blockade of lateral epiphyseal arteries that supply approximately 80% of the femoral head (7) can, in part, be attributed to their anatomical predisposition. It is nonetheless unclear whether ischemia is the initiating event or is secondary to local cellular or vascular bed damage (8).It is further surprising that osteonecrosis is not a cardinal feature of adrenocorticotropic hormone (ACTH)-producing adenomas (9), where glucocorticoid excess is profound. A question therefore arises-does ACTH protect against glucocorticoid-induced osteonecrosis? Indeed, one of our groups has documented functional ACTH receptors (MC2Rs) on osteoblasts; their activation enhances cell proliferation (10). These data are consistent with the presence of receptors for other anterior pituitary hormones, FSH and TSH, on bone cells, as well as with the description of another pituitary-bone axis, in which these hormones bypass traditional endocrine targets to regulate bone mass directly (11-13).We were thus prompted to investigate whether glucocorticoidinduced osteonecrosis could, i...