interleukin-8 and Bone-Neoplasms

It is increasingly evident that the microenvironment of bone can influence the cancer phenotype in many ways that favor growth in bone. The ability of cancer cells to adhere to bone matrix and to promote osteoclast formation are key requirements for the establishment and growth of bone metastases. Several cytokine products of breast cancers (e.g. PTHrP, IL-11, IL-8) have been shown to act upon host cells of the bone microenvironment to promote osteoclast formation, allowing for excessive bone resorption. The increased release of matrix-derived growth factors, especially TGF-β, acts back upon the tumor to facilitate further tumor expansion and enhance cytokine production, and also upon osteoblasts to suppress bone formation. This provides a self-perpetuating cycle of bone loss and tumor growth within the skeleton. Other contributing factors favoring tumor metastasis and colonization in bone include the unique structure and stiffness of skeletal tissue, along with the diverse cellular composition of the marrow environment (e.g. bone cells, stromal fibroblasts, immune cells), any of which can contribute to the phenotypic changes that can take place in metastatic deposits that favor their survival. Additionally, it is also apparent that breast cancer cells begin to express different bone specific proteins as well as proteins important for normal breast development and lactation that allow them to grow in bone and stimulate bone destruction. Taken together, these continually emerging areas of study suggest new potential pathways important in the pathogenesis of bone metastasis and potential areas for targeting therapeutics.

Topics: Bone and Bones; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cytokines; Female; Humans; Interleukin-11; Interleukin-8; Neoplasms; Osteoblasts; Osteoclasts; Osteogenesis; Parathyroid Hormone-Related Protein; Transforming Growth Factor beta

Bone metastases interact with the bone microenvironment. Cancer cells modulate the functions of osteoblasts and osteoclasts to induce new bone formation or bone resorption, leading to secondary stimulation of tumor development. Recent findings suggest the involvement of T cells in this process.. Bone metastatic cancer cells produce factors such as parathyroid hormone-related protein, interleukin-7, and interleukin-8 that can recruit or activate T cells. T cells are involved in bone remodeling and can induce osteoclastic resorption. Bone resorption releases transforming growth factor-beta, however, which could suppress T-cell antitumor immune responses. Bisphosphonate antiresorptive drugs are the approved treatment for solid tumor bone metastases. They have recently been found to activate the cytolytic activity of gammadelta T cells. Thus, inhibitors of transforming growth factor-beta or antiresorptive therapies may be effective enhancers of antitumor immune responses in bone.. T cells at the site of bone metastases may be functionally suppressed by factors in the bone microenvironment. Instead of acting against tumor cells, they may increase bone resorption, making bone a privileged site for tumor growth.

Topics: Bone Neoplasms; Humans; Interleukin-7; Interleukin-8; Lymphocyte Activation; Models, Immunological; Neoplasm Metastasis; Parathyroid Hormone-Related Protein; T-Lymphocytes

Bone metastases lead to hypercalcemia, bone pain, fractures, and nerve compression. They cause increased morbidity and mortality in patients with advanced breast cancer. Animal models reproduce many of the features seen in patients with breast cancer and permit identification of tumor- and bone-derived factors important in skeletal metastasis. These factors provide novel targets for therapeutic interventions. Specific tumor-bone molecular interactions mediated by these factors drive a vicious cycle that perpetuates skeletal metastases. In breast cancer, osteolytic metastases are most common, but mixed and osteoblastic metastases occur in a significant number of patients. Parathyroid hormone-related protein is a common osteolytic factor, and vascular endothelial growth factor and interleukins 8 and 11 also contribute. Osteoblastic metastases can be caused by tumor-secreted endothelin-1 (ET-1), but there are a variety of other potential osteoblastic factors. Stimulation of osteoblasts can paradoxically increase osteoclast function, as bone-synthesizing osteoblasts are the main regulators of bone-destroying osteoclasts. Coexpression of osteolytic and osteoblastic factors can thus produce mixed metastases or increased osteolysis. Cancer treatments, especially sex steroid deprivation therapies, stimulate bone loss. Bone resorption results in the release of bone growth factors, which may unintentionally increase the formation of bone metastases by activating the vicious cycle. Clinically approved bisphosphonates prevent bone resorption and reduce the release of bone growth factors. Parathyroid hormone-related protein-neutralizing antibody, inhibitors of the receptor activator of nuclear factor-kB ligand pathway, and ET-1 receptor antagonists are in clinical trials. These agents act on bone cells rather than tumor cells. Recent experiments identify new potential targets for prevention of bone metastases.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Diphosphonates; Female; Humans; Interleukin-11; Interleukin-8; Models, Animal; Osteoblasts; Osteolysis; Parathyroid Hormone-Related Protein; Vascular Endothelial Growth Factor A; Women's Health

Breast cancer shows a predilection for metastasis to bone. Interestingly, approximately 80% of patients with breast cancer also have bone metastases develop at some point during the course of their disease. Osteolytic breast cancer induces bonedestruction via the stimulation of osteoclasts. Breast cancer cells produce many known stimulators of bone resorption with significant research effort focused on the role of parathyroid hormone-related protein (PTHrP). However, a recent prospective clinical trial has questioned the primary role of PTHrP in this process. The overexpression of interleukin-8 (IL-8) in metastatic breast cancer cells prompted additional investigation of the role of IL-8 in osteolysis. Recombinant IL-8 induces the expression of RANKL mRNA and protein in osteoblastic cells and stimulates formation of bone resorbing osteoclasts, even in the absence of RANKL. The ability of IL-8 to directly stimulate osteoclastogenesis via RANKL dependent and independent mechanisms suggests it may play an important role in the process of osteoclast formation and function. Therefore, we propose that cytokines such as IL-8 are involved in the early stages of breast cancer metastasis and initiate the process of osteoclastic bone resorption. In this modified model of breast cancer metastasis to bone, PTHrP expression is induced later to stimulate the vicious cycle of bone destruction.

Topics: Bone Neoplasms; Breast Neoplasms; Female; Gene Expression Regulation, Neoplastic; Humans; Interleukin-8; Osteoblasts; Osteoclasts; Osteolysis; Parathyroid Hormone-Related Protein

Many molecular mechanisms regulate prostate carcinoma pathogenesis, proliferation, and progression to bone metastases. The basic molecular mechanisms are endocrine, paracrine, autocrine, and intracrine. These mechanisms can be mediated by a variety of agents, including gonadal and adrenal steroids, retinoic acid and vitamin D derivatives, neuroendocrine factors, growth factors, cytokines, lymphokine, and bone factors. Prominent among them is parathyroid hormone-related protein (PTHrP).. The author studied the expression and regulation of PTHrP production in prostate carcinoma cells with nucleic acid and immunochemical probes for the polypeptide. The robust expression of this oncoprotein by prostate carcinoma has been demonstrated. In the current study the author reviews his results and the studies of other investigators regarding PTHrP and the variety of bioactive factors produced by prostate cells.. PTHrP is expressed by most prostate carcinoma. It also is expressed by normal and hyperplastic prostate cells, and there is a gradient of expression that peaks in malignant prostate cells. PTHrP is processed by carcinoma cells into peptides that have unique biologic effects. Among them are regulation of growth and cytokine expression. It has been observed that the effect of PTHrP can be mediated by novel intracrine pathways in prostate carcinoma. These mechanisms influence transduction of growth regulatory signaling pathways, cell proliferation, immunoregulation, and angiogenesis.. The current study identified PTHrP among the bioactive prostate factors that appear to participate in prostate carcinoma pathogenesis and progression. This oncofetal protein is commonly expressed by prostate carcinoma, and its regulatory interactions with other bioactive prostate cell products play an important role in the pathobiology of prostate carcinoma. Understanding these regulatory interactions among prostate carcinoma, its cell products, and the skeleton continues to provide insights into the pathogenesis of this disease entity and may provide clues to clinical management.

Topics: Bone Neoplasms; Humans; Interleukin-6; Interleukin-8; Male; Neovascularization, Pathologic; Parathyroid Hormone-Related Protein; Prostatic Neoplasms; Proteins

Inflammation is proposed to influence tumor response in radiotherapy (RT). Clinical studies to investigate the relationship between inflammatory markers and RT response is warranted to understand the variable RT efficacy in patients with painful bone metastases.. To evaluate the association between inflammatory markers and analgesic response to RT in patients with painful bone metastases.. Adult patients from 7 European study sites undergoing RT for painful bone metastases were included in this prospective and longitudinal analysis. The association between RT response and 17 inflammatory markers at baseline, as well as the association between RT response and the changes observed in inflammatory markers between baseline and three and eight weeks after RT, was analyzed with univariate regression analyses. Baseline analyses were adjusted for potential clinical predictors of RT response.. None of the inflammatory markers were significantly associated with an upcoming RT response in the analysis of 448 patients with complete baseline data. In patients available for follow-up, the three-week change in TNF (P 0.017), IL-8 (P 0.028), IP-10 (P 0.032), eotaxin (P 0.043), G-CSF (P 0.033) and MCP-1 (P 0.002) were positively associated with RT response, while the three-week change in CRP (P 0.006) was negatively associated.. Results from this study show an association between RT response and change in pro-inflammatory mediators and indicate that inflammation may be important to achieve an analgesic RT response in patients with painful bone metastases. None of the investigated inflammatory markers were found to be pre-treatment predictors of RT response.

Topics: Adult; Analgesics; Bone Neoplasms; Chemokine CXCL10; Granulocyte Colony-Stimulating Factor; Humans; Inflammation; Interleukin-8; Pain; Palliative Care; Prospective Studies

Osteosarcoma has been reported with treatment failure in up to 40% of cases. Our laboratory had identified genes involved in the PPARγ pathway to be associated with doxorubicin (DOX) resistance. We hence used PPARγ agonist pioglitazone (PIO) to modulate DOX resistance. DOX-resistant cell line (143B-DOX) was developed by gradient exposure to DOX. The cytotoxicity to PIO and in combination with DOX was assayed in vitro, followed by HPLC to estimate the metabolites of PIO in the presence of microsomes (HLMs). Gene expression studies revealed the mechanism behind the cytotoxicity of PIO. Further, the effects were evaluated in mice bearing 143B-DOX tumors treated either with PIO (20 mg/kg/p.o or 40 mg/kg/p.o Q1D) alone or in combination with DOX (0.5 mg/kg/i.p Q2W). 143B-DOX was 50-fold resistant over parental cells. While PIO did not show any activity on its own, the addition of HLMs to the cells in culture showed over 80% cell kill within 24 h, possibly due to the metabolites of PIO as determined by HPLC. In combination with DOX, PIO had shown synergistic activity. Additionally, cytotoxicity assay in the presence of HLMs revealed that PIO on its own showed promising activity compared to its metabolites-hydroxy pioglitazone and keto pioglitazone. In vivo studies demonstrated that treatment with 40 mg/kg/p.o PIO alone showed significant activity, followed by a combination with DOX. Gene expression studies revealed that PIO could modulate drug resistance by downregulating MDR1 and IL8. Our study suggests that PIO can modulate DOX resistance in osteosarcoma cells.

Topics: Animals; Antibiotics, Antineoplastic; ATP Binding Cassette Transporter, Subfamily B, Member 1; Bone Neoplasms; Cell Line, Tumor; Disease Models, Animal; Doxorubicin; Drug Resistance, Neoplasm; Humans; Hypoglycemic Agents; Interleukin-8; Male; Mice, Nude; Osteosarcoma; Pioglitazone; Xenograft Model Antitumor Assays

The anesthesia procedure in tumor-type total knee arthroplasty (TKA) may contribute to systemic inflammatory response. Therefore, we aim to investigate the effectiveness and safety of general and spinal anesthesia in patients with tumor-type TKA.. Twenty-five patients with tumors around the knee undergoing primary unilateral TKA were randomly divided into the general anesthesia group (n = 13) and spinal anesthesia group (n = 12). Knee joint HSS scores and Western Ontario and McMaster University osteoarthritis index (WOMAC osteoarthritis) were recorded before surgery and 12 months after surgery. Visual analogue scale, C-reactive protein (CPR), tumor necrosis factor-α (TNF-α), and interleukin-8 (IL-8) concentration were measured preoperatively (T0), on the day of the operation (T1), and on the first day (T2) after the operation. Complications in the two groups were recorded.. The operative time, intraoperative blood loss, postoperative drainage, tourniquet time, and complication rate were not significantly different between the general anesthesia and spinal anesthesia groups (all p > 0.05). There were no significant differences in CPR (7.6 ± 3.1, 8.1 ± 4.1, 91.3 ± 24.2 vs. 7.1 ± 2.9, 7.6 ± 3.8, 85.1 ± 19.3 pg/mL, respectively), IL-8 (12.2 ± 6.6, 13.4 ± 7.3, 19.2 ± 10.5 vs. 11.9 ± 5.7, 12.9 ± 8.6, 22.2 ± 12.4 pg/mL, respectively), and TNF-α (2.5 ± 1.7, 2.2 ± 1.9, 2.8 ± 2.1 vs. 2.4 ± 1.3, 2.7 ± 2.1, 2.9 ± 1.6 pg/mL, respectively) between the two groups at T0, T1, and T2 (all p > 0.05). There were no statistical differences in pre- and postoperative HSS knee scores (39.78 ± 11.3, 90.24 ± 15.3 vs. 42.68 ± 12.5, 91.21 ± 16.3) and WOMAC indexes (49.89 ± 7.9, 25.12 ± 6.2 vs. 51.3 ± 8.3, 23.15 ± 5.3) between the two groups (p > 0.05).. General anesthesia and spinal anesthesia in patients with tumor-type TKA had the same effectiveness and safety.

Topics: Aged; Anesthesia, General; Anesthesia, Spinal; Arthroplasty, Replacement, Knee; Blood Loss, Surgical; Bone Neoplasms; C-Reactive Protein; Drainage; Female; Humans; Interleukin-8; Knee Joint; Male; Middle Aged; Operative Time; Postoperative Complications; Systemic Inflammatory Response Syndrome; Treatment Outcome; Tumor Necrosis Factor-alpha; Visual Analog Scale

Approximately 70% of patients with advanced breast cancer develop bone metastases, accompanied by complications, such as bone pain, fracture, and hypercalcemia. However, our understanding of the molecular mechanisms that govern this process remains fragmentary. Osterix (Osx) is a zinc finger-containing transcription factor essential for osteoblast differentiation and bone formation. Here, we identified the functional roles of Osx in facilitating breast cancer invasion and bone metastasis. Osx upregulation was associated with lymph node metastasis and was negatively prognostic for overall survival. Knockdown of Osx inhibited invasion of breast cancer and osteolytic metastasis by downregulating MMP9, MMP13, VEGF, IL-8, and PTHrP, which are involved in invasion, angiogenesis, and osteolysis; overexpression of Osx had the opposite effect. Moreover, MMP9 was a direct target of Osx and mediated the Osx-driven invasion of breast cancer cells. Together, our data showed that Osx facilitates bone metastasis of breast cancer by upregulating the expression of a cohort of genes that contribute to steps in the metastatic cascade. These findings suggest that Osx is an attractive target for the control of bone metastasis of breast cancers.

Topics: Adult; Aged; Aged, 80 and over; Animals; Bone Neoplasms; Breast Neoplasms; Carcinoma, Ductal; Cell Line, Tumor; Female; HEK293 Cells; Heterografts; Humans; Interleukin-8; Matrix Metalloproteinase 13; Matrix Metalloproteinase 9; Mice; Mice, Nude; Middle Aged; Neoplasm Invasiveness; Parathyroid Hormone-Related Protein; Prognosis; Sp7 Transcription Factor; Transfection; Up-Regulation; Vascular Endothelial Growth Factor A

The loss of appropriate cell adhesion normally induces apoptosis via a process termed anoikis. The aim of this study was to investigate the effects of mesenchymal stem cells (MSCs) in the cancer microenvironment on the anoikis resistance and pulmonary metastasis of osteosarcoma (OS) cells, and to evaluate the critical role of the interleukin (IL)-8/C-X-C chemokine receptor (CXCR) 1/Akt-signaling pathway in these processes. Metastatic OS subtype cells, which did or did not interact with MSC-conditioned medium (MSC-CM) in vitro, were isolated from the pulmonary site and named Saos2-lung-M. Both MSC-CM and IL-8 treatment increased the anoikis resistance of Saos2 cells in vitro. Moreover, exogenous MSC-CM promoted the survival and metastasis of Saos2 cells in nude mice. Saos2-lung-M cells were more malignant and resistant to anoikis than parental cells. MSCs secreted IL-8, thereby protecting OS cells from anoikis. Blocking the IL-8/CXCR1/Akt pathway via CXCR1 knockdown inhibited the pulmonary metastasis of Saos2-lung-MSCs and prolonged the survival of tumor-bearing mice. In conclusion, MSCs enhanced OS cell resistance to anoikis and pulmonary metastasis via regulation of the IL-8/CXCR1/Akt pathway. These findings suggest that MSCs can "select for" OS cells with high metastatic potential in vivo, and highlight CXCR1 as a key target in the regulation of pulmonary metastasis of OS cells.

Topics: Animals; Anoikis; Bone Neoplasms; Cells, Cultured; Culture Media, Conditioned; Disease Progression; Gene Expression Regulation, Neoplastic; Humans; Interleukin-8; Lung Neoplasms; Male; Mesenchymal Stem Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Osteosarcoma; Proto-Oncogene Proteins c-akt; Receptors, Interleukin-8A; Signal Transduction; Tumor Microenvironment

Osteosarcoma (OS), a malignant tumor of bone, kills through aggressive metastatic spread almost exclusively to the lung. Mechanisms driving this tropism for lung tissue remain unknown, though likely invoke specific interactions between tumor cells and other cells within the lung metastatic niche. Aberrant overexpression of ΔNp63 in OS cells directly drives production of IL-6 and CXCL8. All these factors were expressed at higher levels in OS lung metastases than in matched primary tumors from the same patients. Expression in cell lines correlated strongly with lung colonization efficiency in murine xenograft models. Lentivirus-mediated expression endowed poorly metastatic OS cells with increased metastatic capacity. Disruption of IL-6 and CXCL8 signaling using genetic or pharmaceutical inhibitors had minimal effects on tumor cell proliferation in vitro or in vivo, but combination treatment inhibited metastasis across multiple models of metastatic OS. Strong interactions occurred between OS cells and both primary bronchial epithelial cells and bronchial smooth muscle cells that drove feed-forward amplification of IL-6 and CXCL8 production. These results identify IL-6 and CXCL8 as primary mediators of OS lung tropism and suggest pleiotropic, redundant mechanisms by which they might effect metastasis. Combination therapy studies demonstrate proof of concept for targeting these tumor-lung interactions to affect metastatic disease.

Topics: Adolescent; Adult; Animals; Antineoplastic Combined Chemotherapy Protocols; Bone and Bones; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Child; Cytokine Receptor gp130; Drug Evaluation, Preclinical; Follow-Up Studies; Humans; Hydrazines; Interleukin-6; Interleukin-8; Lung; Lung Neoplasms; Male; Mice; Osteosarcoma; Primary Cell Culture; Quinoxalines; Receptors, Interleukin-8A; Sulfonamides; Xenograft Model Antitumor Assays; Young Adult

Chemokine cysteine-X-cysteine motif ligand 8 (CXCL8) is up-regulated in many malignancies, indicating that CXCL8 takes part in tumor progression. However, the expression and function of CXCL8 in osteosarcoma remained not fully elucidated. In this study, expressions of 12 cytokines and chemokines were measured in the serum from 12 of normal controls (NCs) and 25 of osteosarcoma patients. The human osteosarcoma cell line MG-63 was stimulated by recombinant CXCL8 to further analyze invasion, proliferation, apoptosis, cell cycles, cytokine secretions, and signaling pathways. We found that serum concentrations of CXCL8 and vascular endothelial growth factor were elevated in osteosarcoma patients in comparison with those in NCs. CXCL8 stimulation led to enhancement of invasion and suppression of late stage apoptosis in MG-63 cells. Moreover, secretions of MMPs by MG-63 cells were also increased upon stimulation. However, early stage apoptosis, proliferation, and cell cycles were not affected by CXCL8 treatment. Furthermore, CXCL8 stimulation induced elevations of phosphorylated PI3K and Akt, but not PKC or FAK. In conclusion, our findings suggested that CXCL8 enhanced the invasion and suppressed late stage apoptosis of osteosarcoma cells probably via influencing PI3K/Akt signaling pathway and elevating the expression of MMPs. CXCL8 may promote disease progression of osteosarcoma as a protumorigenic molecule, and may be served as a new therapeutic target for osteosarcoma.

Topics: Adult; Apoptosis; Bone Neoplasms; Cell Cycle; Cell Line, Tumor; Cell Proliferation; Female; Humans; Interleukin-8; Male; Neoplasm Invasiveness; Osteosarcoma; Phosphatidylinositol 3-Kinases; Proto-Oncogene Proteins c-akt; Signal Transduction; Vascular Endothelial Growth Factor A

Bone density is controlled by interactions between osteoclasts, which resorb bone, and osteoblasts, which deposit it. The semaphorins and their receptors, the plexins, originally shown to function in the immune system and to provide chemotactic cues for axon guidance, are now known to play a role in this process as well. Emerging data have identified Semaphorin 4D (Sema4D) as a product of osteoclasts acting through its receptor Plexin-B1 on osteoblasts to inhibit their function, tipping the balance of bone homeostasis in favor of resorption. Breast cancers and other epithelial malignancies overexpress Sema4D, so we theorized that tumor cells could be exploiting this pathway to establish lytic skeletal metastases. Here, we use measurements of osteoblast and osteoclast differentiation and function in vitro and a mouse model of skeletal metastasis to demonstrate that both soluble Sema4D and protein produced by the breast cancer cell line MDA-MB-231 inhibits differentiation of MC3T3 cells, an osteoblast cell line, and their ability to form mineralized tissues, while Sema4D-mediated induction of IL-8 and LIX/CXCL5, the murine homologue of IL-8, increases osteoclast numbers and activity. We also observe a decrease in the number of bone metastases in mice injected with MDA-MB-231 cells when Sema4D is silenced by RNA interference. These results are significant because treatments directed at suppression of skeletal metastases in bone-homing malignancies usually work by arresting bone remodeling, potentially leading to skeletal fragility, a significant problem in patient management. Targeting Sema4D in these cancers would not affect bone remodeling and therefore could elicit an improved therapeutic result without the debilitating side effects.

Topics: Animals; Antigens, CD; Bone Neoplasms; Breast Neoplasms; Calcification, Physiologic; Cell Line, Tumor; Female; Heterografts; Humans; Interleukin-8; Mice; Neoplasm Metastasis; Neoplasm Proteins; Neoplasm Transplantation; Semaphorins

During the bone metastatic process, tumor cells and bone cells drive a vicious cycle stimulating growth and activity of each other. We here address how low molecular weight protein tyrosine phosphatase (LMW-PTP) could be involved in this process.. We targeted LMW-PTP by siRNA and evaluated the effect of various soluble factors released to the culture medium by the MDA-MB-435 breast cancer cell line, in RAW 264.7 osteoclastogenesis.. We showed that these soluble factors did not change RAW 264.7 osteoclastogenic potential. The knockdown of the LMW-PTP slow isoform decreased osteoclastogenesis of RAW 264.7, showing less active Src. The knockdown of LMW-PTP and its slow isoform decreased the release of IL-8 but not IL-6 in MDA-MB-435.. The LMW-PTP slow isoform can be an important protein in bone metastatic disease, with a fundamental role in the interplay between tumor cells and osteoclasts, through the regulation of Src activity and IL-8 secretion.

Topics: Adenocarcinoma; Animals; Bone Neoplasms; Breast Neoplasms; Cell Differentiation; Cell Line, Tumor; Culture Media, Conditioned; Interleukin-6; Interleukin-8; Mice; Neoplasm Proteins; Osteoclasts; Phosphorylation; Phosphotyrosine; Protein Isoforms; Protein Processing, Post-Translational; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins; RANK Ligand; RAW 264.7 Cells; RNA Interference; RNA, Small Interfering; src-Family Kinases

This study aimed to evaluate the prognostic implications of insulin-like growth factor-II mRNA binding protein-3 (IMP3) and podoplanin (PDPN) as therapeutic targets against oral squamous cell carcinoma (OSCC) with bone invasion.. We elucidated the correlation of IMP3 and PDPN expression with bone invasion in 160 OSCC tissue specimens, and assessed a mouse calvarium xenograft model using an IMP3- and PDPN-depleted OSCC cell line.. The retrospective analysis revealed that the expression of IMP3 and PDPN is significantly correlated with T stage, lymph node metastasis, and the overall survival of OSCC patients. In addition, the dual expression of IMP3 and PDPN but not the single expression of either IMP3 or PDPN was associated with bone invasion and the number of osteoclasts in patients with OSCC. In support of these findings, IMP3 or PDPN depletion inhibited the invasive capacity of OSCC cells in a three-dimensional culture system, tumorigenesis, and regional bone destruction in a xenograft mouse model. In addition, IMP3 or PDPN depletion inhibited the expression of interleukin (IL)-6 and IL-8 in OSCC cells, and decreased the expression of receptor activator of NF-κB ligand (RANKL) in xenograft tumor tissues of OSCC.. These results suggest that IMP3 and PDPN may have strong influence on the pathogenesis of OSCC, especially in bone invasion, and may serve as novel therapeutic targets with prognostic implications for bone-invasive OSCC.

Topics: Adult; Aged; Aged, 80 and over; Animals; Bone Neoplasms; Carcinoma, Squamous Cell; Cell Transformation, Neoplastic; Female; Head and Neck Neoplasms; Heterografts; Humans; Interleukin-11; Interleukin-6; Interleukin-8; Lymphatic Metastasis; Male; Membrane Glycoproteins; Mice; Middle Aged; Mouth Neoplasms; Osteoclasts; Prognosis; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Retrospective Studies; RNA-Binding Proteins; RNA, Messenger; Squamous Cell Carcinoma of Head and Neck

p63 is a structural homolog within the 53 family encoding two isoforms, ΔNp63 and TAp63. The oncogenic activity of ΔNp63 has been demonstrated in multiple cancers, however the underlying mechanisms that contribute to tumorigenesis are poorly characterized. Osteosarcoma (OSA) is the most common primary bone tumor in dogs, exhibiting clinical behavior and molecular biology essentially identical to its human counterpart. The purpose of this study was to evaluate the potential contribution of ΔNp63 to the biology of canine OSA. As demonstrated by qRT-PCR, nearly all canine OSA cell lines and tissues overexpressed ΔNp63 relative to normal control osteoblasts. Inhibition of ΔNp63 by RNAi selectively induced apoptosis in the OSA cell lines overexpressing ΔNp63. Knockdown of ΔNp63 upregulated expression of the proapoptotic Bcl-2 family members Puma and Noxa independent of p53. However the effects of ΔNp63 required transactivating isoforms of p73, suggesting that ΔNp63 promotes survival in OSA by repressing p73-dependent apoptosis. In addition, ΔNp63 modulated angiogenesis and invasion through its effects on VEGF-A and IL-8 expression, and STAT3 phosphorylation. Lastly, the capacity of canine OSA cell lines to form pulmonary metastasis was directly related to expression levels of ΔNp63 in a murine model of metastatic OSA. Together, these data demonstrate that ΔNp63 inhibits apoptosis and promotes metastasis, supporting continued evaluation of this oncogene as a therapeutic target in both human and canine OSA.

Topics: Animals; Apoptosis; Bone Neoplasms; Cell Line, Tumor; Cell Survival; Dogs; Female; Gene Expression Regulation, Neoplastic; Gene Knockdown Techniques; Interleukin-8; Lung Neoplasms; Mice; Mice, SCID; Neoplasm Invasiveness; Neovascularization, Pathologic; Osteoblasts; Osteosarcoma; Phosphorylation; Protein Isoforms; Proto-Oncogene Proteins c-bcl-2; RNA Interference; RNA, Small Interfering; Sarcoma, Experimental; STAT3 Transcription Factor; Transcription Factors; Tumor Protein p73; Tumor Suppressor Protein p53; Tumor Suppressor Proteins; Vascular Endothelial Growth Factor A

This is the first study to demonstrate that benzo(a)-pyrene (BaP) was able to enhance the production of parathyroid hormone‑related protein (PTHrP) by human non‑small cell lung cancer H460 cells. Such effect would further contribute to bone metastasis of lung cancer by increasing osteoclastogenesis. This study is also the first to reveal that tricetin (TCN), a flavonoid derivative found in Myrtaceae pollen and Eucalyptus honey, was able to reverse BaP‑mediated bone resorption activity of lung cancer cells. Human non‑small cell lung cancer H460 cells were treated with BaP to generate conditioned medium. When osteoblasts were cultured with BaP‑H460‑CM, their expression of osteoclastogenesis activator macrophage colony‑stimulating factor (M‑CSF) and receptor activator of nuclear factor κB ligand (RANKL) was increased. BaP‑H460‑CM reduced the production of osteoprotegerin (OPG), an osteoclastogenesis inhibitor, in osteoblasts. Osteoclastogenesis and bone resorption activity of H460 cells were increased by BaP‑H460‑CM. With BaP‑mediated PTHrP upregulation, IL‑8 secretion in H460 cells was increased contributing to human non‑small cell lung cancer‑mediated osteoclast differentiation and bone resorption. Moreover, TCN suppressed BaP‑mediated bone resorption. Therefore, TCN may be a novel agent for treatment of non‑small cell lung cancer patients with bone metastasis.

Topics: Antineoplastic Agents; Benzo(a)pyrene; Bone Neoplasms; Bone Resorption; Carcinoma, Non-Small-Cell Lung; Cells, Cultured; Chromones; Enzyme-Linked Immunosorbent Assay; Flavonoids; Humans; Interleukin-8; Lung Neoplasms; Macrophage Colony-Stimulating Factor; Osteoblasts; Osteoprotegerin; Parathyroid Hormone-Related Protein; RANK Ligand; Real-Time Polymerase Chain Reaction

Skeletal metastases of breast cancer and subsequent osteolysis connote a dramatic change in the prognosis for the patient and significantly increase the morbidity associated with disease. The cytokine interleukin 8 (IL-8/CXCL8) is able to directly stimulate osteoclastogenesis and bone resorption in mouse models of breast cancer bone metastasis. In this study, we determined whether circulating levels of IL-8 were associated with increased bone resorption and breast cancer bone metastasis in patients and investigated IL-8 action in vitro and in vivo in mice. Using breast cancer patient plasma (36 patients), we identified significantly elevated IL-8 levels in bone metastasis patients compared with patients lacking bone metastasis (p<0.05), as well as a correlation between plasma IL-8 and increased bone resorption (p<0.05), as measured by NTx levels. In a total of 22 ER+ and 15 ER- primary invasive ductal carcinomas, all cases examined stained positive for IL-8 expression. In vitro, human MDA-MB-231 and MDA-MET breast cancer cell lines secrete two distinct IL-8 isoforms, both of which were found to stimulate osteoclastogenesis. However, the more osteolytic MDA-MET-derived full length IL-8(1-77) had significantly higher potency than the non-osteolytic MDA-MB-231-derived IL-8(6-77), via the CXCR1 receptor. MDA-MET breast cancer cells were injected into the tibia of nude mice and 7days later treated daily with a neutralizing IL-8 monoclonal antibody. All tumor-injected mice receiving no antibody developed large osteolytic bone tumors, whereas 83% of the IL-8 antibody-treated mice had no evidence of tumor at the end of 28days and had significantly increased survival. The pro-osteoclastogenic activity of IL-8 in vivo was confirmed when transgenic mice expressing human IL-8 were examined and found to have a profound osteopenic phenotype, with elevated bone resorption and inherently low bone mass. Collectively, these data suggest that IL-8 plays an important role in breast cancer osteolysis and that anti-IL-8 therapy may be useful in the treatment of the skeletal related events associated with breast cancer.

Topics: Animals; Bone Neoplasms; Bone Screws; Breast Neoplasms; Carcinoma, Ductal, Breast; Cell Line, Tumor; Female; Humans; Interleukin-8; Mice; Mice, Nude; Mice, Transgenic; Osteolysis

Serum levels of sRANKL, RANK, OPG, IL-8, IL-6, IL-16, MMP-2, and calcitonin were measured by ELISA in patients with malignant, borderline, and benign bone tumors and in healthy individuals (control). Serum levels of RANK, OPG, IL-8, IL-6, and the OPG/sRANKL ratio were significantly higher, while the level of MMP-2 was significantly lower in patients with bone tumors than in controls. Serum concentration of IL-16 in osteosarcoma patients was significantly lower than in chondrosarcoma patients. No significant differences between bone sarcomas of different differentiation were detected for any of the studied markers. Calcitonin level depended on the tumor location and type.

Topics: Adolescent; Adult; Aged; Bone Neoplasms; Calcitonin; Case-Control Studies; Chondrosarcoma; Chordoma; Female; Gene Expression; Humans; Interleukin-16; Interleukin-6; Interleukin-8; Male; Matrix Metalloproteinase 2; Middle Aged; Neoplasms; Osteoprotegerin; Osteosarcoma; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Bone is a common site of metastasis for lung cancer, and is associated with significant morbidity and a dismal prognosis. MicroRNAs (miRNAs) are increasingly implicated in regulating the progression of malignancies.. The efficacy of miR-33a or anti-miR-33a plasmid was assessed by Real-time PCR. Luciferase assays were using One-Glo Luciferase Assay System. Measurement of secreted factors was determined by ELISA kit.. We have found that miR-33a, which is downregulated in lung cancer cells, directly targets PTHrP (parathyroid hormone-related protein), a potent stimulator of osteoclastic bone resorption, leading to decreased osteolytic bone metastasis. We also found that miR-33a levels are inversely correlated with PTHrP expression between human normal bronchial cell line and lung cancer cell lines. The reintroduction of miR-33a reduces the stimulatory effect of A549 on the production of osteoclastogenesis activator RANKL (receptor activator of nuclear factor kappa-B ligand) and M-CSF (macrophage colony-stimulating factor) on osteoblasts, while the expression of PTHrP is decreased in A549 cells. miR-33a overexpression also reduces the inhibitory activity of A549 on the production of OPG (osteoprotegerin), an osteoclastogenesis inhibitor. In addition, miR-33a-mediated PTHrP downregulation results in decreased IL-8 secretion in A549, which contributes to decreased lung cancer-mediated osteoclast differentiation and bone resorption.. These findings have led us to conclude that miR-33a may be a potent tumor suppressor, which inhibits direct and indirect osteoclastogenesis through repression of PTHrP.. miR-33a may even predict a poor prognosis for lung cancer patients.

Topics: Bone Neoplasms; Bone Resorption; Cell Differentiation; Cell Line, Tumor; Down-Regulation; Gene Expression Regulation, Neoplastic; Genes, Tumor Suppressor; Humans; Interleukin-8; Lung Neoplasms; MicroRNAs; Neoplasm Metastasis; Neoplasm Proteins; Osteoclasts; Osteoprotegerin; Parathyroid Hormone-Related Protein; RANK Ligand; RNA, Neoplasm

Poorly differentiated thyroid carcinoma (PDTC) is a newly recognized histological type of malignant thyroid tumor, accounting for about 2 - 13% of all thyroid carcinomas. PDTC is considered as a morphologically and biologically intermediate stage between well-differentiated thyroid carcinoma and anaplastic thyroid carcinoma. PDTC preferentially manifests bone metastases. We here established a cell line from a resected tumor specimen from a 70-year-old male patient with PDTC who presented with multiple bone metastases. This new thyroid tumor cell line was designated as DH-14-3 and was subsequently grown in culture for several years. DH-14-3 cells express thyroglobulin in the cytoplasm and thyroid transcription factor-1 in the nuclei, both proteins of which are specific markers for the thyroid gland. Importantly, triiodothyronine (T3) was detected in the cultured medium of DH-14-3 cells, in which, however, thyroxine (T4) was undetectable. Moreover, DH-14-3 cells secreted interleukin-8, transforming growth factor-β1, vascular endothelial growth factor, matrix metalloproteinase-1 and parathyroid hormone-related protein, all of which may be responsible for the aggressiveness or bone metastasis of PDTC. Thus, the production of these proteins may reflect the metastatic potential of this cell line. DH-14-3 cells also express CXC chemokine receptor-4 and epidermal growth factor receptor, and carry a missense mutation in the p53 tumor suppressor gene. In fact, transplantation of DH-14-3 cells into the back of nude mice resulted in the formation of tumors, thereby confirming the capability of tumorigenesis. DH-14-3 cells may be useful for investigating the biological features of PDTC and will contribute to the therapeutic study of thyroid cancer.

Topics: Aged; Animals; Bone Neoplasms; Cell Differentiation; Cell Line, Tumor; Humans; Interleukin-8; Male; Matrix Metalloproteinase 1; Mice; Neoplasm Metastasis; Neoplasm Transplantation; Parathyroid Hormone-Related Protein; Real-Time Polymerase Chain Reaction; Thyroid Neoplasms; Transforming Growth Factor beta1; Tumor Suppressor Protein p53; Vascular Endothelial Growth Factor A

Lysophosphatidic acid (LPA) is a bioactive lipid with a growth factor-like activity on a large range of cell types. Several pieces of evidence raise the possibility that LPA may play an important role in bone metastasis. Bone is a frequent metastatic site for oral cancer. However, the role of LPA in the progression of oral cancer metastasis to the bone is poorly understood. Here, we provide evidence for the role of LPA in the progression of oral cancer bone metastases and its regulatory mechanism. LPA induced the secretion of IL-6 and IL-8 in oral squamous cell carcinoma (OSCC). LPA-stimulated secretion of IL-6 and IL-8 is partly dependent on the LPA and EGF receptor (EGFR) pathways. ERK1/2 and Akt-mediated NF-κB and AP-1 were responsible for the LPA-induced IL-6 and IL-8 secretion. Moreover, conditioned medium (CM) derived from the LPA-stimulated OSCC supported osteoclast formation in bone marrow-derived macrophages (BMMs). Neutralization against both human IL-6 and IL-8 suppressed osteoclast formation induced by CM derived from the LPA-stimulated OSCC. Direct treatment with recombinant IL-6 (rIL-6) and/or soluble IL-6 receptor (sIL-6R), or IL-8 (rIL-8) reproduced the effect of the CM derived from the LPA-stimulated OSCC on osteoclast formation. In addition, CM derived from the LPA-stimulated OSCC induced receptor activator of nuclear factor (NF)-κB ligand (RANKL) expression in human osteoblasts and direct treatment with rIL-6 and/or sIL-6R or rIL-8 mimicked the effect of the CM derived from the LPA-stimulated OSCC for RANKL expression. Taken together, LPA may be a potent inducer of osteolytic factor IL-6 and IL-8 in OSCC. LPA-induced IL-6 and IL-8 exerted propound effects on RANKL expression in osteoblast and thereby promoted osteoclast formation from osteoclast precursors.

Topics: Animals; Biological Assay; Blotting, Western; Bone Neoplasms; Bone Resorption; Carcinoma, Squamous Cell; Humans; Interleukin-6; Interleukin-8; Lysophospholipids; Mice; Mouth Neoplasms; Osteoclasts; RANK Ligand; Reverse Transcriptase Polymerase Chain Reaction

Vascular endothelial growth factor (VEGF) is a signal protein produced by cells that stimulates vasculogenesis and angiogenesis. VEGF is believed to implicate poor prognosis in various cancers. The overexpression of VEGF may be an early step in the process of metastasis.. ELISA was used to investigate the levels of VEGF, bFGF and IL8 in human bone metastatic LNCaP-derivative C4-2B prostate cancer cell line and its parental cell line, LNCaP and to determine the effect of bevacizumab on reducing the level of VEGF. Cell proliferation assay, invasion assay and in vitro angiogenesis assay were performed under the condition with bevacizumab or control IgG.. Human bone metastatic LNCaP-derivative C4-2B prostate cancer cell line expressed a higher level of VEGF than its parental primary prostate cancer cell line LNCaP. The effect of bevacizumab is dose-dependent and time-dependent: 100 μg/mL of bevacizumab and 3-day treatment was more effective than low-dose and lesser-day treatment for decreasing the level of VEGF. Bevacizumab is able to suppress cell proliferation, angiogenesis and invasion in human bone metastatic C4-2B prostatic cancer cell line.. The overexpression of VEGF can be inhibited by bevacizumab in human bone metastatic cancer cell line. The behaviors of metastasis involving proliferation, angiogenesis and invasion are suppressed by anti-VEGF therapy.

Topics: Antibodies, Monoclonal, Humanized; Bevacizumab; Bone Neoplasms; Cell Line, Tumor; Cell Proliferation; Fibroblast Growth Factors; Gene Expression Regulation, Neoplastic; Humans; Interleukin-8; Male; Neoplasm Invasiveness; Neovascularization, Pathologic; Prostatic Neoplasms; Vascular Endothelial Growth Factor A

We have delineated TGFβ signaling pathways in the production of osteolytic factors interleukin-8 and interleukin-11 in breast cancer cells with different bone metastases potential. Bone seeking MDA-MB-231(hm) cells expressed higher levels of IL-11, but lower levels of IL-8 compared to MDA-MB-231 cells. MCF-7 cells (mainly osteoblastic) did not express IL-8 or IL-11; MDA-MB-468 cells (weakly metastatic) expressed IL-8, but not IL-11. The up-regulation of IL-11 and IL-8 was associated with the rapid activation of SMAD2/3 and p38 MAPK through the TGFβ/TGFβR system. Analysis of TGFβ receptors indicated that MCF-7 cells do not express TGFβRII, and MDA-MB-468 cells do not express SMAD4. Inactivation of SMAD4 or p38PMAPK gene via RNAi resulted in the inhibition of IL-11 and IL-8 production in MDA-MB-231(hm) cells; and over-expression of SMAD4 gene resulted in IL-11 production in MDA-MB-468 cells. TGFβ-1 induced SMAD3 translocation to the nuclei in MDA-MB-231, MDA-MB-231(hm) as well as in SMAD4 deficient MDA-MB-468, indicating that an alternate non-canonical pathway could be responsible for TGFβ-1 induced cytokine production in MDA-MB-468 cells. Thus, four breast cancer cell lines used in this study show differential expression and up-regulation of the osteolytic factors in response to TGFβ-1 that involves both SMAD pathway, a non-canonical SMAD pathway, as well as p38 MAPK pathways.

Topics: Bone Neoplasms; Breast Neoplasms; Cell Line, Tumor; Cell Nucleus; Enzyme-Linked Immunosorbent Assay; Female; Humans; Interleukin-11; Interleukin-8; Neoplasm Metastasis; p38 Mitogen-Activated Protein Kinases; Receptors, Transforming Growth Factor beta; RNA, Small Interfering; Signal Transduction; Smad Proteins; Transforming Growth Factor beta

Breast cancer frequently metastasizes to bone, where it leads to secondary tumor growth, osteolytic bone degradation, and poor clinical prognosis. Hydroxyapatite Ca(10)(PO(4))(6)(OH)(2) (HA), a mineral closely related to the inorganic component of bone, may be implicated in these processes. However, it is currently unclear how the nanoscale materials properties of bone mineral, such as particle size and crystallinity, which change as a result of osteolytic bone remodeling, affect metastatic breast cancer. We have developed a two-step hydrothermal synthesis method to obtain HA nanoparticles with narrow size distributions and varying crystallinity. These nanoparticles were incorporated into gas-foamed/particulate leached poly(lactide-co-glycolide) scaffolds, which were seeded with metastatic breast cancer cells to create mineral-containing scaffolds for the study of breast cancer bone metastasis. Our results suggest that smaller, poorly-crystalline HA nanoparticles promote greater adsorption of adhesive serum proteins and enhance breast tumor cell adhesion and growth relative to larger, more crystalline nanoparticles. Conversely, the larger, more crystalline HA nanoparticles stimulate enhanced expression of the osteolytic factor interleukin-8 (IL-8). Our data suggest an important role for nanoscale HA properties in the vicious cycle of bone metastasis and indicate that mineral-containing tumor models may be excellent tools to study cancer biology and to define design parameters for non-tumorigenic mineral-containing or mineralized matrices for bone regeneration.

Topics: Bone and Bones; Bone Neoplasms; Breast Neoplasms; Durapatite; Female; Humans; Interleukin-8; Materials Testing; Nanoparticles; Neoplasm Metastasis; Particle Size; Tissue Scaffolds; Tumor Cells, Cultured; X-Ray Diffraction

Advanced-stage breast cancers frequently metastasize to the bones and cause bone destruction, but the underlying mechanism is not fully understood. This study presents evidence that TGF-β-activated protein kinase 1 (TAK1) signaling in tumor cells promotes bone destruction by metastatic breast carcinoma cells, controlling expression of prometastatic factors including matrix metalloproteinase (MMP) 9 and COX2. Suppression of TAK1 signaling by dominant-negative TAK1 (dn-TAK1) in breast carcinoma MDA-MB-231 cells impairs bone colonization by carcinoma cells and bone osteolysis in the intracardiac injection model. Mechanistic studies showed that inhibition of TAK1 by dn-TAK1 or siRNA blocked expression of factors implicated in bone metastasis, such as MMP-9, COX2/PTGS2, parathyroid hormone-related protein (PTHrP) and interleukin 8 (IL-8), but did not affect activation of p38MAPK by TGF-β. TAK1 signaling is mediated by TAK1-binding partners TAB1, TAB2, and TAB3. Carcinoma cells express elevated mRNA levels of TAB2 and TAB3, whereas the TAB1 expression is noticeably low. Accordingly, depletion of TAB2 by siRNA reduced expression of MMP-9 and COX2. Together, these studies show that the TAK1-TAB2-TAB3 signaling axis is critical for carcinoma-induced bone lesions, mediating expression of proinvasive and osteolytic factors. These findings identify the TAK1-TAB2 axis as a potential therapeutic target in bone metastasis.

Topics: Adaptor Proteins, Signal Transducing; Animals; Bone Neoplasms; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Cyclooxygenase 2; Female; Humans; Interleukin-8; Male; MAP Kinase Kinase Kinases; Matrix Metalloproteinase 9; Mice; Mice, SCID; Prostatic Neoplasms; RNA, Small Interfering; Signal Transduction; Transforming Growth Factor beta

N-myc downstream regulated gene 2 (NDRG2) is involved in invasion and metastasis of cancer, furthermore it is frequently down-regulated in prostate cancer. Herein we evaluated the effect of NDRG2 overexpression on invasiveness and bone destruction in prostate cancer. The human prostate cancer cell line PC-3 and DU145 were infected with Ad-NDRG2 or Ad-LacZ. Overexpression of NDRG2 not only inhibited the growth of the cells, but also suppressed invasiveness of the cells in an in vitro assay. PC-3 cells infected with Ad-NDRG2 or Ad-LacZ were injected into the tibias of nude mice. Four weeks later, we found the mice injected with PC-3 cells overexpressing NDRG2 had smaller tumors and less bone destruction. These results demonstrate that NDRG2 overexpression can inhibit tumor growth and invasion, furthermore, it can decrease bone destruction caused by prostate cancer bone metastasis.

Topics: Animals; Blotting, Western; Bone Neoplasms; Cell Line, Tumor; Cell Movement; Cell Proliferation; Gene Expression Regulation, Neoplastic; Humans; Interleukin-8; Male; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Mice; Mice, Inbred BALB C; Mice, Nude; Microscopy, Fluorescence; Neoplasm Invasiveness; Neoplasm Transplantation; Prostatic Neoplasms; Transfection; Transplantation, Heterologous; Tumor Burden; Tumor Suppressor Proteins

To find the optimal proportion of Composite Fructus Psoralea and Fructus Cnidii (CFPC) for inhibiting the bone metastasis of breast cancer by way of exploring its acting mechanism viewing from OPG/RANKL/RANK system.. The human bone metastasis of breast cancer model was established by injecting tumor cells of MDA-MB-231BO cell line into the left cardiac ventricle of nude mice. The modeled mice were randomly divided into seven groups: the blank group administered with normal saline by gastrogavage, the positive control group with zoledronic acid via peritoneal injection, and the 5 tested group with CFPC in different proportions of Fructus Psoralea and Fructus Cnidii, i.e., (A, 4:0; B, 3:1; C, 1:1; D, 1:3, and E 0:4), given by gastric infusion. The treatment started from 1 week after modeling and lasted for six weeks. By the end of the experiment, the metastatic foci in bone were imaged by radionuclide tracing method and X-ray photograph, and separated for detecting gene and protein expressions of osteoprotegerin (OPG), receptor activator of nuclear factor-kappaB ligand (RANKL), interleukin-8 (IL-8), parathyroid hormone-related protein (PTHrP), macrophage colony stimulating factor (MCSF) by Real-time PCR and Western blot respectively.. Inhibition of bone metastasis gene was displayed to some extent in all the tested groups treated with CFPC, showing an increased level of OPG mRNA expression (It was 60.343 +/- 6.274 in the tested group C), and decreased mRNA expressions of IL-8, PTHrP, MCSF, RANKL (218.010 +/- 12.802, 232.399 +/- 14.354, 319.831 +/- 5.322, and 195.701 +/- 4. 862, respectively in the tested group C). The optimal effect was shown in the tested group C, showing significant difference to that in the blank group (P < 0.01). Meanwhile, the OPG in the bone metastatic foci could be up-regulated and protein expressions of RANKL/IL-8/PTHrP/MCSF down-regulated in all the tested groups. The optimal effect was shown in the tested group C, with significant difference from those of the normal saline group.. CFPC could inhibit the bone metastasis of breast cancer through activating OPG/RANKL/RANK pathway. Among different proportions of Fructus Psoralea and Fructus Cnidii, 1:1 was the best one.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Cell Line, Tumor; Coumarins; Female; Ficusin; Interleukin-8; Macrophage Colony-Stimulating Factor; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Metastasis; Osteoprotegerin; Parathyroid Hormone-Related Protein; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B

Bone is a frequent target of lung cancer metastasis, which is associated with significant morbidity and a dismal prognosis. This study analyzed the soluble factors secreted by lung cancer cells, which are responsible for increasing osteoclast differentiation. Addition of recombinant human interleukin-8 (rhIL-8), present in large amounts in A549-conditioned medium (CM) and NCI-H460-CM, mimicked the inductive effect of A549-CM and NCI-H460-CM on osteoclastogenesis. In contrast, depletion of interleukin-8 (IL-8) from A549-CM and NCI-H460-CM decreased the osteoclastogenesis-inductive properties of A549-CM and NCI-H460-CM. Induction of osteoclast differentiation by lung cancer-derived-CM and rhIL-8 was associated with increased phospholipase D (PLD) activation, and the activations of protein kinase C (PKC) alpha/betaII, extracellular signal-regulated kinase (ERK) 1/2 and AKT/the mammalian target of rapamycin (mTOR). Blocking PLD by a specific inhibitor significantly decreased osteoclast formation by inhibiting PKCs activation and subsequently attenuating the phosphorylation of ERK1/2. PLD inhibitor also completely decreased AKT and mTOR phosphorylation, whereas phosphatidylinositol-3-kinase (PI3K) inhibitor only partially decreased mTOR phosphorylation, suggesting that mTOR activation by PLD is through both PI3K/AKT-dependent and PI3K/AKT-independent manner. In addition, blocking AKT and ERK1/2 by a specific inhibitor also suppressed lung cancer-derived-CM and rhIL-8-induced osteoclast differentiation. Moreover, treatment of peripheral blood mononuclear cells with sera from invasive lung cancer patients increased the formation of osteoclasts. Our study suggests that IL-8 or IL-8-mediated PLD/PKC/ERK1/2 or PLD/AKT signaling is an attractive therapeutic target for osteolytic bone metastases in lung cancer patients.

Topics: Bone Neoplasms; Cells, Cultured; Extracellular Signal-Regulated MAP Kinases; Humans; Interleukin-8; Intracellular Signaling Peptides and Proteins; Lung Neoplasms; MAP Kinase Signaling System; Osteoclasts; Phosphatidylinositol 3-Kinases; Phospholipase D; Protein Kinase C-alpha; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins c-akt; RANK Ligand; Signal Transduction; TOR Serine-Threonine Kinases

Skeletal disorders are a common complication of breast cancer and will be found in the vast majority of women with metastatic disease. Our study showed that rosmarinic acid (RA) could inhibit the migration of MDA-MB-231BO human bone-homing breast cancer cells dose-dependently. Furthermore, in ST-2 murine bone marrow stromal cells cultured with RA there was a significant and dose-dependent increase in alkaline phosphatase (ALP) activity, with the number and size of mineralized nodules increasing. According to Western blot and quantitative real-time PCR assay, RA may inhibit bone metastasis from breast carcinoma mainly via the pathway of the receptor activator of NF kappaB ligand (RANKL)/RANK/osteoprotegerin (OPG) and by simultaneously suppressing the expression of interleukin-8 (IL-8). RA may thus be a good candidate for a new therapeutic approach in bone metastasis from breast carcinoma.

Topics: Alkaline Phosphatase; Animals; Antineoplastic Agents, Phytogenic; Blotting, Western; Bone and Bones; Bone Marrow; Bone Neoplasms; Breast Neoplasms; Carcinoma; Cell Line, Tumor; Cinnamates; Depsides; Dose-Response Relationship, Drug; Female; Humans; Interleukin-8; Mice; NF-kappa B; Osteoprotegerin; Phytotherapy; Plant Extracts; Prunella; RANK Ligand; Reverse Transcriptase Polymerase Chain Reaction; Rosmarinic Acid; Stromal Cells

Lung cancer is the leading cause of cancer-related deaths. The morbidity and mortality of lung cancer have markedly increased in the past decade with at least 75% of patients with lung cancer having evidence of metastases at the time of diagnosis. It frequently metastasizes to bone resulting in osteolytic lesions with unknown mechanisms. The aim of this study was to identify factors that mediate lung cancer-induced osteoclast activity in vivo. Using a human cytokine antibody array, we first determined cytokine levels in a conditioned medium collected from non-small cell lung cancer A549 and H1299 cells and the non-neoplastic human bronchial epithelial BEAS2B cells. Both A549 and H1229 cells produced significantly higher amount of several cytokines including monocyte chemotactic protein 1 (MCP-1) and interleukin 8 (IL-8) compared with BEAS2B cells. These findings were confirmed by ELISA. From clinical serum specimens, we also observed that MCP-1 and IL-8 levels were increased in lung cancer patients with bone metastases compared with the patients with localized tumor. Next, we investigated the effects of MCP-1 on osteoclast formation in vitro using murine bone marrow-derived monocytes. A549 conditioned medium induced osteoclast formation that was inhibited by neutralizing antibodies against MCP-1. Finally, A549 cells were stably transfected with MCP-1 short hairpin RNA. The MCP-1 knockdown A549 cells were implanted into the tibia of severe combined immunodeficient mice for 4 weeks. The MCP-1 knockdown significantly diminished A549 cell growth. We conclude that MCP-1 promotes lung cancer-induced osteoclast activity and thus bone resorptive lesions in vivo.

Topics: Adult; Aged; Aged, 80 and over; Animals; Bone Neoplasms; Carcinoma, Non-Small-Cell Lung; Cell Line, Tumor; Chemokine CCL2; Culture Media, Conditioned; Enzyme-Linked Immunosorbent Assay; Humans; Interleukin-8; Lung Neoplasms; Male; Mice; Mice, SCID; Middle Aged; Osteoclasts

Bone metastasis is a hallmark of advanced prostate and breast cancers, yet the critical factors behind attraction of tumors to the skeleton have not been validated. Here, we investigated the involvement of cathepsin K in the progression of prostate tumors in the bone, which occurs both by direct degradation of bone matrix collagen I and by cleavage of other factors in the bone microenvironment. Our results demonstrated that bone marrow-derived cathepsin K is capable of processing and thereby modulating SPARC, a protein implicated in bone metastasis and inflammation. The coincident up-regulation of SPARC and cathepsin K occurred both in vivo in experimental prostate bone tumors, and in vitro in co-cultures of bone marrow stromal cells with PC3 prostate carcinoma cells. PC3-bone marrow stromal cell interaction increased secretion and processing of SPARC, as did co-cultures of bone marrow stromal cells with two other cancer cell lines. In addition, bone marrow stromal cells that were either deficient in cathepsin K or treated with cathepsin K inhibitors had significantly reduced secretion and cleavage of SPARC. Increases in secretion of pro-inflammatory cytokines (ie, interleukin-6, -8) coincident with overexpression of cathepsin K suggest possible mechanisms by which this enzyme contributes to tumor progression in the bone. This is the first study implicating bone marrow cathepsin K in regulation of biological activity of SPARC in bone metastasis.

Topics: Animals; Bone Marrow; Bone Marrow Cells; Bone Neoplasms; Cathepsin K; Cell Communication; Cell Line, Tumor; Coculture Techniques; Humans; Interleukin-6; Interleukin-8; Male; Mice; Mice, SCID; Neoplasm Invasiveness; Osteonectin; Prostatic Neoplasms; Stromal Cells; Up-Regulation

Breast cancer preferentially metastasizes to the skeleton, a hospitable environment that attracts and allows breast cancer cells to thrive. Growth factors released as bone is degraded support tumor cell growth, and establish a cycle favoring continued bone degradation. While the osteoclasts are the direct effectors of bone degradation, we found that osteoblasts also contribute to bone loss. Osteoblasts are more than intermediaries between tumor cells and osteoclasts. We have presented evidence that osteoblasts contribute through loss of function induced by metastatic breast cancer cells. Metastatic breast cancer cells suppress osteoblast differentiation, alter morphology, and increase apoptosis. In this study we show that osteoblasts undergo an inflammatory stress response in the presence of human metastatic breast cancer cells. When conditioned medium from cancer cells was added to human osteoblasts, the osteoblasts were induced to express increased levels of IL-6, IL-8, and MCP-1; cytokines known to attract, differentiate, and activate osteoclasts. Similar findings were seen with murine osteoblasts and primary murine calvarial osteoblasts. Osteoblasts are co-opted into creating a microenvironment that exacerbates bone loss and are prevented from producing matrix proteins for mineralization. This is the first study implicating osteoblast produced IL-6, IL-8 (human; MIP-2 and KC mouse), and MCP-1 as key mediators in the osteoblast response to metastatic breast cancer cells.

Topics: Animals; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Calcification, Physiologic; Carcinoma; Cell Communication; Cell Line, Tumor; Chemokine CCL2; Culture Media, Conditioned; Cytokines; Female; Humans; Interleukin-6; Interleukin-8; Mice; Neoplasm Metastasis; Osteitis; Osteoblasts; Osteoclasts; Osteogenesis; Stress, Physiological

Cyclooxygenase-2 (COX-2) overexpression by a primary tumor correlates with poor prognosis in breast cancer, including early spread to bone. Interleukin-8 (IL-8) stimulates osteoclastogenesis and resorption of bone, and elevated IL-8 levels predict early metastatic spread of breast cancer. The purpose of this study was to test our hypothesis that tumors that overexpress COX-2 induce IL-8 production.. We cotransfected MCF-10A (nonmalignant breast epithelial) cells, as well as MDA-231 (highly metastatic human breast cancer) cell lines with a pSG5-COX-2 vector and pEF1a-Luc-IRES-Neo vector (luciferase reporter). COX-2 overexpression was confirmed by Western blot and PGE2 (a product of the COX-2 pathway) immunoassay. IL-8 production was measured by immunoassay. In vivo testing used a nude mouse model to measure COX-2 and IL-8 production from breast cancer cells that had metastasized to bone (bone-seeking clones (BSCs)). Long bone metastases were localized and quantified by luciferase imaging (Xenogen IVIS system) and X-ray. BSCs were isolated and cultured and then tested for the production of PGE2 and IL-8.. COX-2 overexpression caused a 4- to 5-fold increase in IL-8 production in both MCF-10A and MDA-231 cells in vitro. In vivo, we observed that the MDA-231-BSC (metastatic cells isolated from bone metastases) produced significantly greater levels of both PGE2 and IL-8 compared to the parental MDA-231 cells (P < 0.01). In contrast to the results obtained with these estrogen receptor-negative cell lines, COX-2 expression failed to induce IL-8 in the MCF-7 estrogen receptor-positive breast cancer cell line. Treatment with the COX-2 inhibitor NS-398 at a low 1-mu[scap]M dose reduced the production of IL-8 in COX-2-transfected MDA-231 cells by 30%, thus confirming the involvement of COX-2 in IL-8 induction.. COX-2 expression induced formation of PGE2 and IL-8 in breast cancer cells. Since PGE2 and IL-8 stimulate osteoclasts to resorb bone, COX-2 inhibition is a potential target for treatment to prevent bone metastases.

Topics: Animals; Bone Neoplasms; Breast Neoplasms; Cell Line, Tumor; Cyclooxygenase 2; Cyclooxygenase 2 Inhibitors; Female; Humans; Interleukin-8; Mice; Mice, Nude; Protein Processing, Post-Translational

Prostate cancers (PCas) produce factors that can serve as biomarkers for tumor metastasis and bone progression. Transduced GFP expression by cancer cells can be imaged to monitor therapy. We exploited both concepts by developing a GFP-expressing PCa cell line that expresses PTHrP and studying it in an animal model of malignancy with methods that assess the skeletal progression of this tumor.. We developed a GFP-producing PCa cell line by stable transduction of PC-3 PCa cells. This PC-3 variant was used to study tumor progression in an immunocompromised mouse model. Skeletal progression of the PCa cells and the effects of pamidronate administration were evaluated radiologically, fluorometrically, and by measurement of serum tumor markers.. The PC-3 cells produced extensive bone lesions when injected into the tibia of immunocompromised mice. The skeletal progression of the PC-3 cells could be monitored by GFP optical imaging, X-ray, and by measurements of tumor products in serum, notably PTHrP and OPG. Pamidronate treatment reduced tumor burden as assessed at autopsy by imaging and biomarkers.. Pamidronate treatment exhibited anti-tumor effects that were reflected by decreases in serum PTHrP, OPG, and by GFP and radiological imaging procedures. Imaging of GFP expression enables real-time monitoring of tumor growth in the bone. PTHrP and OPG may be useful as tumor biomarkers for PCa that has metastasized to bone. This novel human PCa model can be used to study the clinical potential of diagnostic and therapeutic modalities in the skeletal progression of PCas.

Topics: Adenocarcinoma; Animals; Antineoplastic Agents; Biomarkers, Tumor; Bone Neoplasms; Calcium; Carrier Proteins; Cell Line, Tumor; Diphosphonates; Disease Models, Animal; Glycoproteins; Green Fluorescent Proteins; Humans; Interleukin-6; Interleukin-8; Male; Membrane Glycoproteins; Mice; Mice, SCID; Microscopy, Fluorescence; Osteoprotegerin; Pamidronate; Parathyroid Hormone-Related Protein; Prostatic Neoplasms; Radiography; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Transduction, Genetic

Parathyroid hormone-related protein (PTHrP) is an oncoprotein that is expressed in many malignancies as well as normal tissues. At essentially every site of expression, PTHrP regulates cell growth and proliferation. We and other investigators have previously reported that PTHrP is widely expressed by prostate cancer. For this tumor, there are substantial in vitro and correlative data that PTHrP expression regulates the progression of the tumor, especially in bone, but little direct data. We studied the effects of PTHrP expression on prostate cancer behavior directly in a mouse model of human prostate cancer cells that were transfected to express different forms of the polypeptide and then injected intraskeletally. Skeletal progression of the prostate cancer cells was evaluated radiologically and by measurement of serum tumor markers. PTHrP transfection converted a non-invasive cell line into one that progressed in the skeleton: Injection of the PTHrP transfected cells resulted in greater tumor progression in bone when compared to non-transfected cells, and this effect was also influenced by non-amino terminal peptides of PTHrP. Serum measurements of PTHrP, IL-6, IL-8, and calcium reflected tumor burden. Our experiments provide direct in vivo evidence that PTHrP expression results in the skeletal progression of prostate cancer cells.

Topics: Animals; Bone Neoplasms; Calcium; Cell Line, Tumor; Disease Models, Animal; Disease Progression; Humans; Interleukin-6; Interleukin-8; Male; Mice; Neoplasm Transplantation; Parathyroid Hormone-Related Protein; Prostatic Neoplasms

Bone is a common site of cancer metastasis. Breast, prostate, and lung cancers show a predilection to metastasize to bone. Recently, we reported that the chemokine interleukin 8 (IL-8) stimulates both human osteoclast formation and bone resorption. IL-8 mRNA expression was surveyed in a panel of human breast cancer lines MDA-MET, MDA-MB-231, MDA-MB-435, MCF-7, T47D, and ZR-75, and the human lung adenocarcinoma cell line A549. IL-8 mRNA expression was higher in cell lines with higher osteolytic potential in vivo. Human osteoclast formation was increased by MDA-MET or A549 cell-conditioned medium, but not by MDA-MB-231. Pharmacologic doses of receptor activator of nuclear factor-kappaB (RANK)-Fc or osteoprotogerin had no effect on the pro-osteoclastogenic activity of the conditioned medium; however, osteoclast formation stimulated by conditioned medium was inhibited 60% by an IL-8-specific neutralizing antibody. The data support a model in which tumor cells cause osteolytic bone destruction independently of the RANK ligand (RANKL) pathway. Tumor-produced IL-8 is a major contributor to this process. The role of secreted IL-8 isoforms was examined by surface-enhanced laser desorption/ionization time-of-flight mass spectrometry, which detected distinct IL-8 isoforms secreted by MDA-MET and MDA-231 cells, suggesting different pro-osteoclastogenic activities of the two IL-8-derived peptides. These data indicate that (a) osteoclast formation induced by MDA-MET breast cancer cells and A549 adenocarcinoma cells is primarily mediated by IL-8, (b) cell-specific isoforms of IL-8 with distinct osteoclastogenic activities are produced by tumor cells, and (c) tumor cells that support osteoclast formation independent of RANKL secrete other pro-osteoclastogenic factors in addition to IL-8.

Topics: Adenocarcinoma; Animals; Bone Neoplasms; Breast Neoplasms; Carrier Proteins; Cell Line, Tumor; Culture Media, Conditioned; Humans; Interleukin-8; Lung Neoplasms; Membrane Glycoproteins; Mice; Mice, Nude; Osteoclasts; Osteolysis; Protein Isoforms; RANK Ligand; Receptor Activator of Nuclear Factor-kappa B; RNA, Messenger

Aalinkeel et al. (1) have recently reported that gene expression of angiogenic factors correlates with metastatic potential of prostate cancer cells. The rationale for the study of Aalinkeel et al. is that a variety of growth factors, among them interleukin-8 (il-8), can induce angiogenesis (2). Further, parathyroid hormone related peptide (PTHrP) acts to induce il-8 production in prostate cancer cells via an intracrine pathway independent of its classical nuclear localization sequence. This novel pathway could mediate the effects of PTHrP on the progression of prostate cancer (3). We measured il-8 in the serum of 39 men with biopsy-proven prostate cancer. Their average age was 69 +/- 9 (mean +/- SD). Serum il-8 was measured with an automated chemiluminometric high sensitivity il-8 protein assay (Immulite, Diagnostic Products Corporation, Los Angeles, CA). We noted a significant elevation of il-8 in men with bone metastases, diagnosed by Tc-99 MDP bone scan, when compared to men with localized disease (Figure 1). Aalinkeel et al. found that il-8 was significantly higher in the more metastatic PC-3 and DU-145 prostate cancer cell lines, when compared to the poorly metastatic LnCAP cells. The results of our study of il-8 in men with prostate cancer support the findings of Aalinkeel et al. Therefore, new anti-angiogenic therapies targeting specific genes controlling prostate tumor metastasis may be of benefit in treating prostate cancer.

Topics: Aged; Bone Neoplasms; Cell Line, Tumor; Humans; Interleukin-8; Male; Middle Aged; Parathyroid Hormone-Related Protein; Prostatic Neoplasms

The role of lysophosphatidic acid (LPA) in cancer is poorly understood. Here we provide evidence for a role of LPA in the progression of breast cancer bone metastases. LPA receptors LPA(1), LPA(2), and LPA(3) were expressed in human primary breast tumors and a series of human breast cancer cell lines. The inducible overexpression of LPA(1) in MDA-BO2 breast cancer cells specifically sensitized these cells to the mitogenic action of LPA in vitro. In vivo, LPA(1) overexpression in MDA-BO2 cells enhanced the growth of subcutaneous tumor xenografts and promoted bone metastasis formation in mice by increasing both skeletal tumor growth and bone destruction. This suggested that endogenous LPA was produced in the tumor microenvironment. However, MDA-BO2 cells or transfectants did not produce LPA. Instead, they induced the release of LPA from activated platelets which, in turn, promoted tumor cell proliferation and the LPA(1)-dependent secretion of IL-6 and IL-8, 2 potent bone resorption stimulators. Moreover, platelet-derived LPA deprivation in mice, achieved by treatment with the platelet antagonist Integrilin, inhibited the progression of bone metastases caused by parental and LPA(1)-overexpressing MDA-BO2 cells and reduced the progression of osteolytic lesions in mice bearing CHO-beta3wt ovarian cancer cells. Overall, our data suggest that, at the bone metastatic site, tumor cells stimulate the production of LPA from activated platelets, which enhances both tumor growth and cytokine-mediated bone destruction.

Topics: Animals; Blood Platelets; Bone and Bones; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cell Line; Cell Line, Tumor; Cell Proliferation; Cricetinae; Culture Media; Cytokines; Disease Progression; Dose-Response Relationship, Drug; Doxycycline; Enzyme-Linked Immunosorbent Assay; Female; Humans; Immunohistochemistry; Interleukin-6; Interleukin-8; Ki-67 Antigen; Lysophospholipids; Mice; Mice, Inbred BALB C; Mice, Nude; Mitogens; Models, Biological; Neoplasm Metastasis; Osteoclasts; Osteolysis; Phospholipase D; Platelet Activation; Platelet Aggregation; Reverse Transcriptase Polymerase Chain Reaction; RNA; Time Factors; Transfection

We determined whether blockade of the epidermal growth factor receptor (EGF-R) signaling pathway by oral administration of the EGF-R tyrosine kinase inhibitor (PKI 166) alone or in combination with injectable Taxol inhibits the growth of PC-3MM2 human prostate cancer cells in the bone of nude mice.. Male nude mice implanted with PC-3MM2 cells in the tibia were treated with oral administrations of PKI 166 or PKI 166 plus injectable Taxol beginning 3 days after implantation. The incidence and size of bone tumors and destruction of bone were determined by digitalized radiography. Expression of epidermal growth factor (EGF), EGF-R, and activated EGF-R in tumor cells and tumor-associated endothelial cells was determined by immunohistochemistry.. Oral administration of PKI 166 or PKI 166 plus injectable Taxol reduced the incidence and size of bone tumors and destruction of bone. Immunohistochemical analysis revealed that PC-3MM2 cells growing adjacent to the bone expressed high levels of EGF and activated EGF-R, whereas tumor cells in the adjacent musculature did not. Moreover, endothelial cells within the bone tumor lesions, but not in uninvolved bone or tumors in the muscle, expressed high levels of activated EGF-R. Treatment with PKI 166 and more so with PKI 166 plus Taxol significantly inhibited phosphorylation of EGF-R on tumor and endothelial cells and induced significant apoptosis and endothelial cells within tumor lesions.. These data indicate that endothelial cells exposed to EGF produced by tumor cells express activated EGF-R and that targeting EGF-R can produce significant therapeutic effects against prostate cancer bone metastasis.

Topics: Administration, Oral; Animals; Antineoplastic Agents, Phytogenic; Blotting, Western; Bone and Bones; Bone Neoplasms; Dose-Response Relationship, Drug; Endothelial Growth Factors; Endothelium, Vascular; ErbB Receptors; Fibroblast Growth Factor 2; Immunohistochemistry; In Situ Nick-End Labeling; Intercellular Signaling Peptides and Proteins; Interleukin-8; Lymphokines; Male; Mice; Mice, Nude; Microscopy, Fluorescence; Neoplasm Metastasis; Neoplasm Transplantation; Paclitaxel; Phosphorylation; Platelet Endothelial Cell Adhesion Molecule-1; Proliferating Cell Nuclear Antigen; Prostatic Neoplasms; Pyrimidines; Pyrroles; Signal Transduction; Tumor Cells, Cultured; Vascular Endothelial Growth Factor A; Vascular Endothelial Growth Factors

Interleukin 8 (IL-8) is a member of the alpha chemokine family of cytokines originally identified as a neutrophil chemoattractant. Recently, we reported that elevated levels of IL-8, but not parathyroid hormone-related protein (PTHrP), correlated with increased bone metastasis in a population of human breast cancer cells. We hypothesized that IL-8 expression by breast cancer cells would either indirectly influence osteoclastogenesis via nearby stromal cells or directly influence osteoclast differentiation and activity. In the present study, we investigated the role of IL-8 in the process of osteoclast formation and bone resorption, which is associated with metastatic breast cancer. The addition of recombinant human (rh) IL-8 (10 ng/ml) to cultures of stromal osteoblastic cells stimulated both RANKL mRNA expression and protein production, with no effect on the expression of osteoprotegerin. In addition, rhIL-8 also directly stimulated the differentiation of human peripheral blood mononuclear cells into bone-resorbing osteoclasts. In these cultures, IL-8 was able to stimulate human osteoclast formation even in the presence of excess (200 ng/ml) RANK-Fc. The effect of IL-8 on osteoclasts and their progenitors was associated with the cell surface expression of the IL-8-specific receptor (CXCR1) on the cells. These results demonstrate a direct effect of IL-8 on osteoclast differentiation and activity. Together, these data implicate IL-8 in the osteolysis associated with metastatic breast cancer.

Topics: Animals; Bone Neoplasms; Bone Resorption; Breast Neoplasms; Cell Line, Tumor; Glycoproteins; Humans; Interleukin-8; Mice; Osteoclasts; Osteolysis; Osteoprotegerin; Receptors, Cytoplasmic and Nuclear; Receptors, Tumor Necrosis Factor; Recombinant Proteins

Metastasis is the process by which tumor cells spread from their site of origin to distant sites after gaining access to the circulatory system. An understanding of the factors contributing to the metastatic potential of breast cancer cells to bone will enhance the prospect of developing new therapies that impede metastasis. In this study, we have used an in vivo selection scheme involving left cardiac ventricle injection into nude mice to identify a highly metastatic human breast cancer cell line (MDA-MET) from a less metastatic (MDA-231) parental cell line. In this model, tumor-bearing mice exhibit features similar to those associated with human metastatic bone disease such as osteolytic bone destruction. After inoculation, MDA-MET cells form devastating lesions within 4 weeks, whereas the parental cells do not, even after 10 weeks. In vitro, the MDA-MET cells have a similar growth rate to the parental MDA-231 cells yet demonstrate distinct adhesive and invasive phenotypes. MDA-MET cells show increased early adhesion to type IV collagen and are significantly more invasive through Matrigel than MDA-231 cells. Analysis of the gene expression profile in the metastatic MDA-MET versus poorly metastatic MDA-231 cells identified relatively few genes whose expression was altered >2-fold. Of particular interest was the lack of parathyroid hormone-related protein (PTHrP) mRNA expression, which was supported at the protein level by immunoradiometric assay. These data support the idea that PTHrP is not predictive of the metastasis of human breast cancer to bone. Another important difference between the two cell lines was the elevated expression by MDA-MET cells of the cytokine IL-8. Reverse transcriptase-PCR and ELISA confirmed the increased expression of IL-8 in MDA-MET cells. In addition, IL-8 mRNA expression is also elevated in a variety of human cancer cell lines with different metastatic potential in vivo. These experiments suggest that the elevated expression of IL-8 (and not PTHrP) by MDA-MET cells is a phenotypic change that may be related to their enhanced ability to metastasize to the skeleton.

Topics: Bone Neoplasms; Breast Neoplasms; Cell Adhesion; Cell Division; Extracellular Matrix; Gene Expression; Humans; Interleukin-8; Neoplasm Invasiveness; Oligonucleotide Array Sequence Analysis; Parathyroid Hormone-Related Protein; Peptide Hormones; RNA, Messenger; Tumor Cells, Cultured

HARA-B cells were established from the bone lesion in nude mice formed after an intracardiac inoculation of the human lung cancer-derived cells (HARA), and production of IL-8 in HARA-B cells was decreased as compared to that in the parental HARA cells. This suggests a possible relationship between IL-8 production and bone metastasis. Thus, we examined the effect of IL-8 on bone metastasis using HARA-B cells transfected with experimental (IL-8-cDNA) and/or control plasmid in the experimental bone metastasis model in nude mice. Growth rates of both cells in vitro were similar. Control cells developed radiologically detectable bone metastases in 50% of nude mice tested, whereas experimental cells did not develop bone metastases. Osteoclastic bone resorption is an important step in the process of bone metastasis, and IL-8 possesses an inhibitory effect on osteoclastic bone resorption. These results suggest that IL-8 suppresses bone metastasis, which might be attributed to the inhibitory effect of IL-8 on osteoclastic bone resorption.

Topics: Animals; Bone Neoplasms; Cell Count; Humans; Interleukin-8; Lung Neoplasms; Male; Mice; Mice, Inbred BALB C; Mice, Nude; Transfection; Tumor Cells, Cultured

We have investigated both constitutive- and cytokine-induced secretion of interleukin-8 (IL-8) and its regulation by dexamethasone and 17 beta-estradiol in normal human bone marrow stromal (HBMS), osteoblast-like cells (hOB), and osteosarcoma MG-63 cells. Although HBMS cells secrete low levels of IL-8 constitutively, treatment with IL-1 beta and tumor necrosis factor-alpha (TNF-alpha) induced IL-8 secretion. Their effects were synergistic but IL-8 production was not affected by 17 beta-estradiol. Human osteosarcoma MG-63 cells also secreted low levels of IL-8 constitutively; the production was induced by IL-1 beta and TNF-alpha and was also not affected by 17 beta-estradiol. The magnitude of the response to cytokine stimulation of IL-8 in MG-63 cells was much lower than that of HBMS and hOB cells, indicating differences in response in normal and osteoblastic osteosarcoma cells. Dexamethasone (10(-7) M) significantly inhibited IL-1 beta plus TNF-alpha stimulated IL-8 production in HBMS, MG-63, and hOB cells. The accumulated results demonstrate that IL-8 is secreted by HBMS, MG-63, and hOB cells, suggesting that IL-8 may play a role in the regulation of bone cell function. These data also emphasize the importance of glucocorticoids in controlling cytokine secretion in HBMS, hOB, and MG-63 cells.

Topics: Bone Marrow; Bone Marrow Cells; Bone Neoplasms; Cells, Cultured; Culture Media, Conditioned; Dexamethasone; Drug Synergism; Enzyme-Linked Immunosorbent Assay; Estradiol; Humans; Interleukin-1; Interleukin-8; Osteoblasts; Osteosarcoma; Ribs; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha