Bone morphogenetic proteins induce apoptosis in multiple myeloma cells by Smad-dependent repression of MYC

Bone morphogenetic proteins (BMPs) have been shown to induce apoptosis and growth arrest in myeloma cells. However, the molecular mechanisms behind these events are not known. The MYC oncogene is a master regulator of cell growth and protein synthesis and MYC overexpression has been proposed to be associated with the progression of multiple myeloma. Here, we show that BMP-induced apoptosis in myeloma cells is dependent on downregulation of MYC. Moreover, the results suggest that targeting the MYC addiction in multiple myeloma is an efficient way of killing a majority of primary myeloma clones. We also found that myeloma cells harboring immunoglobulin (IG)-MYC translocations evaded BMP-induced apoptosis, suggesting a novel way for myeloma cells to overcome potential tumor suppression by BMPs.     

骨形态发生蛋白与肿瘤

骨形态发生蛋白(BMP)是一种多功能的细胞因子,不仅可以促进新骨形成,而且参与调控细胞生长、分化、迁移、凋亡以及胚胎和器官发生等过程.研究显示BMP还与肿瘤的发生和转移密切相关,在肿瘤治疗中具有重要的应用价值.     

Bone marrow fibroblasts induce expression of PI3K/NF-kappaB pathway genes and a pro-angiogenic phenotype in CLL cells

Microarray-based gene expression profiling (GEP) was used to study how stroma modulates the survival of CLL cells in an in vitro coculture model employing the murine fibroblast cell line M2-10B4. CLL cells cultured in direct contact with the stromal layer (STR) showed a significantly better survival than cells cultured in transwell (TW) inserts above the M2-10B4 cells. STR as compared to TW conditions induced a significant up-regulation of PI3K/NF-kappaB pro-survival pathway genes and mediated a pro-angiogenetic switch in the CLL cells by up-regulation of vascular endothelial growth factor (VEGF) and osteopontin (OPN) and down-regulation of the anti-angiogenetic molecule thrombospondin-1 (TSP-1).     

Role of bone morphogenetic proteins in transitional cell carcinoma cells

Bone morphogenetic proteins (BMPs) are pleiotropic growth factors that signal through an interaction with the membrane receptors-type--IA, -IB, and -II (BMP-RIA, -RIB, and -RII, respectively). Although the prototypical members of this group of growth factors were isolated as osteoinductive factors, recently accumulated data have suggested that these factors regulate malignant cells. Herein, we review the data concerning BMPs in transitional cell carcinoma cells.     

Bone morphogenetic protein 7 (BMP7) expression is a potential novel prognostic marker for recurrence in patients with primary melanoma

The purpose of this study was to investigate whether protein expression of bone morphogenetic protein 7 (BMP7) is associated with clinico-pathologic characteristics in benign and malignant melanocytic skin tumors. Tissue microarrays (TMAs) were used to analyze BMP7 expression and the Ki-67 labeling index immunohistochemically. Expression was scored semi quantitatively (0-2+). BMP7 protein expression of any intensity (1+-2+) was detected in 50.2% (153/305) of informative cases. In general, BMP7 expression was significantly induced in malignant melanomas (P< 0.001) and melanoma metastases (P< 0.001), compared to benign nevi. Additionally, expression of BMP7 in primary melanomas was associated with Ki-67 labeling index > 5% suggesting that induction of BMP7 expression is associated with proliferation (P=0.028). None of the other clinical and histological factors analyzed was significantly related to BMP7 expression. Interestingly, lymph node metastases demonstrated a significantly higher BMP7 expression compared to skin metastases (P<0.01). Strong BMP7 expression (score 2+) was significantly associated with shorter tumor recurrence (P< 0.05). In summary, induction of BMP7 expression is frequent in melanomas and may serve as a novel prognostic marker of progression in melanoma patients.     

Basigin (CD147) is expressed on melanoma cells and induces tumor cell invasion by stimulating production of matrix metalloproteinases by fibroblasts

EMMPRIN, which is identical to human basigin (CD147), interacts with fibroblasts and stimulates expression of MMPs, which play an important role in tumor invasiveness and metastasis. In the present study, we demonstrated that coculture of basigin-expressing human MM cells with dermal fibroblasts resulted in the induction of MMP-1, MMP-2, MMP-3 and MT1-MMP production by fibroblasts and of melanoma cell invasion through a reconstituted basement membrane. Antibody to basigin inhibited both the production of MMPs by fibroblasts and the invasiveness of melanoma cells. Expression of basigin and MMPs in MM and surrounding fibroblasts was examined immunohistochemically in 28 specimens from 18 MM patients without metastasis and 10 with metastasis, to investigate whether basigin plays a role in metastasis of MM in vivo. Basigin was expressed in melanoma cells but not in fibroblasts. MM with metastasis had significantly higher basigin expression compared to MM without metastasis. There were significant differences between MMs with and without metastasis in the expression of MMPs in both melanoma cells and fibroblasts. Expression of MMPs in fibroblasts was positively correlated with expression levels of basigin. These immunohistochemic findings indicate that MMPs might be expressed in fibroblasts as well as melanoma cells concomitantly with basigin, which was expressed in melanoma cells more frequently in MM with metastasis. Basigin is highly expressed in melanoma cells and may play an important role in their invasiveness and metastasis by stimulating surrounding fibroblasts to express MMPs.     

Bone morphogenetic protein 7 expression associates with bone metastasis in breast carcinomas.

BACKGROUND: We recently showed that bone morphogenetic protein 7 (BMP7) is overexpressed in primary breast tumors. Here we explored the clinical significance of BMP7 expression in breast cancer. MATERIALS AND METHODS: This study included 483 breast cancer patients with complete clinicopathological information and up to 15 years of follow-up. Samples contained 241 lobular carcinomas, 242 ductal carcinomas, and 40 local recurrences. BMP7 protein expression was determined using immunohistochemistry. RESULTS: BMP7 was expressed in 47% of the primary tumor samples and 13% of the local recurrences. The primary tumors expressed BMP7 more often than the corresponding local recurrences (P = 0.004). BMP7 expression was dependent on the tumor subtype; 57% of the lobular carcinomas but only 37% of the ductal carcinomas were BMP7 positive (P = 0.0001). BMP7 expression was associated with accelerated bone metastasis formation (P = 0.040), especially in ductal carcinomas (P = 0.033), and multivariate analysis confirmed that BMP7 is an independent prognostic indicator for early bone metastasis development (P = 0.032). CONCLUSION: BMP7 is clearly associated with bone metastasis formation and thus might have clinical utility in identification of patients with increased risk of bone metastasis. This is the first time that bone inducing factor BMP7 has been linked to the bone metastasis process in breast cancer.     

Erythropoietin receptor expression in human melanoma cells

Erythropoietin is well known for its role in the control of erythropoiesis, where it acts by binding to its cognate receptor (EpoR) on the surface of erythroid progenitor cells. Here we present the novel finding that the EpoR is also expressed in cells of the melanocytic lineage. It is expressed in transformed cell lines established from normal melanocytes and also in established human melanoma cell lines derived from melanoma metastases, but not in normal primary human melanocytes. The analysis of individual subclones isolated from spontaneously transformed melanocytes revealed that approximately 50% of all the clones examined expressed the EpoR. Further analysis of the individual growth characteristics of EpoR-positive and EpoR-negative clones indicated that, under standard cell culture conditions, expression of the receptor did not affect cell growth. Expression of this receptor is consequently most likely driven by an event that is associated with, but not absolutely required for, the transformed phenotype. While the definite function of this receptor in melanoma cells is still unknown and additional studies are required, our findings support the hypothesis that the EpoR may serve as a progression marker for human melanoma. This observation might be useful in the early diagnosis of melanoma.     

Differential expression of angioregulatory matricellular proteins in posterior uveal melanoma

Metastases from uveal melanoma, the most common primary malignant eye tumour in adults, develop solely via their vascular bed due to the absence of intraocular lymphatics. The present study investigated the expression in this tumour of three matricellular proteins--Secreted Protein Acidic and Rich in Cysteine (SPARC), thrombospondin 1 (TSP1) and thrombospondin 2 (TSP2)--with putative contrasting roles in the regulation of angiogenesis. Immunohistochemical analysis of the three proteins was carried out in paraffin-embedded specimens from 27 posterior uveal melanomas and was corroborated with Western blot analysis of fresh-frozen samples from seven of the tumours. SPARC immunoreactivity was detected in all specimens and defined two categories of tumour: SPARC-rich (21 of 27 specimens) and SPARC-patchy (six of 27 specimens) uveal melanomas. SPARC-rich tumours had a significantly higher proportion of specimen area occupied by blood vessels (P=0.04) and showed a positive association with the presence of epithelioid-type tumoral cells (P=0.101). TSP1 was not detected by either of the methods in any of the tumours analysed. Some immunopositivity for TSP2 was detected in tumour cells in approximately 40% of specimens, but was not associated with survival, tumour vascularity or any other histopathological indices of survival. The pattern of expression of these matricellular proteins in uveal melanoma is consistent with a cooperative mechanism for establishing an enhanced environment favourable to angiogenesis. Interventions inducing TSP1 expression and/or inhibiting SPARC expression may be candidates for therapies directed towards the inhibition of angiogenesis in posterior uveal melanoma.     

Bone morphogenetic protein 4 inhibits cell proliferation and induces apoptosis in glioma stem cells

Glioma stem cells (GSCs), which are originated from transformed neural stem cells, are tumor-initiating cells of glioma, the most common primary malignant neoplasm of the central nervous system. Extensive studies have shown that bone morphogenetic protein 4 (BMP4) plays an important role in the differentiation and proliferation of neural stem cells. To seek the functions and mechanisms of BMP4 in GSCs, GSCs isolated from U87 human glioma cells by using vincristine were exposed to BMP4 protein. This study shows that BMP4 inhibited U87 GSC proliferation (p?相似文献   

Contact stimulation of fibroblasts for tenascin production by melanoma cells

Tenascin, an extracellular matrix glycoprotein, is widely expressed in the stroma of almost all types of solid tumours including malignant melanomas. On the basis of its antiadhesive character, it has been supposed that tenascin accumulation facilitates tumour cell invasion and consequent metastasis formation. We aimed to investigate the mechanism by which melanoma cells can modulate the production of tenascin by host stromal cells. The expression of tenascin in cocultures of fibroblasts and five melanoma cell lines, as well as in fibroblast monocultures treated with melanoma conditioned media, was analysed by immunofluorescent staining and image analysis. Tenascin production could not be observed in control fibroblasts or in melanoma cell monocultures. Faint labelling for tenascin could be detected in fibroblast monocultures treated with melanoma cell conditioned media while a very intense staining for tenascin could be seen in melanoma cell-fibroblast cocultures. The tenascin staining in the cocultures was associated with the fibroblasts that were in close contact with melanoma cells. The level of tenascin production around the fibroblasts in different areas of the cocultures correlated well with the density of melanoma cells. Our results indicate that tenascin production of fibroblasts in the tumour stroma is directly modulated by melanoma cells mainly through cell-to-cell contact signalling.     

Bone morphogenetic protein signalling in colorectal cancer

Much of the current understanding of colorectal cancer stems from the study of rare, inherited colorectal cancer syndromes. Mutations in the bone morphogenetic protein (BMP) pathway have been found in juvenile polyposis, an inherited polyposis syndrome that predisposes to colorectal cancer. The hamartomas that develop in these patients and in BMP pathway mutant mice have a remarkable mesenchymal component. Further evidence in mice suggests a primary role for mesenchymal loss of BMP signalling in hamartoma development. Here, we examine this evidence and question its relevance to sporadic colorectal carcinogenesis.     

Profiling of matrix metalloproteinases and tissue inhibitors of metalloproteinases proteins in bladder urothelial carcinoma

We investigated the matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinase (TIMPs) proteins in transitional cell carcinoma (TCC) cell lines and surgical specimens of the bladder neoplasm. The expression level was correlated to the degree of cellular differentiation and invasiveness of bladder cancer. Panels of six TCC cell lines with different degrees of differentiation were tested with monoclonal antibodies (mAbs) to MMP-1, MMP-2, MMP-3, MMP-9a, MMP-9b, TIMP-1 and TIMP-2 by immunocytochemistry. Gelatin zymography was also conducted on the cell lines for MMP-2 and -9. In addition, immunohistochemistry with the mAbs to MMP and TIM molecules was performed on 30 TCC specimens. We found that TCC cell lines were stained positively for MMP-1 (6/6), weakly for MMP-9a (2/6), MMP9b (5/6) and TIMP-1 (3/6), and negatively for MMP-2 (3/6) and MMP-3 (3/6). Zymographic analysis of the cell lines showed a high level of MMP2 in the MGH-U4 cell line. In bladder cancer surgical specimens, all specimens were positive for MMP1 (30/30), 19 were positive for MMP-2 (63.3%), 21 positive for MMP-9a (70%) and 15 positive for MMP-9b (50%). The expression of MMP-2 was found to be positively correlated with higher-grade tumors (p=0.036) and the expression of MMP-9a and -9b was found to be positively correlated with tumor stage (p=0.012 and 0.023, respectively). However, the expression of MMP-1, MMP-3, TIMP-1 and TIMP-2 was not correlated with either tumor staging or grading. In conclusion, the expression of MMP-2 and -9 was correlated with high-grade or high-stage bladder tumors, respectively. However, this correlation was not observed with TCC cell lines in which high- and low-grade tumors are included. Immunohistochemical results on tumor lesions may have more clinical relevance, since in a given tumor microenvironment the interaction among tumor cells in situ and tumor-associated cells, such as neutrophils, macrophages, lymphocytes and endothelial cells, as well as environmental factors (hypoxia and pH), cytokines and growth factors released by these cells may be required for TCC to express selective MMPs and TIMPs. The selective expression of these molecules then regulates tumor progression.     

Bone morphogenetic protein and activin signaling in colorectal cancer

The roles in colon cancer pathogenesis of the transforming growth factor family members bone morphogenetic protein (BMP) and activin have only recently been studied but are increasingly recognized as key. Like their more heavily investigated relative, transforming growth factor β, both BMP and activin are growth-suppressive in normal colonocytes, and their canonical intracellular SMAD signaling is disrupted to abate this suppression. For BMP, there is evidence that non-SMAD signaling pathways may mediate cell proliferation and contribute to the metastatic behavior of colon cancer. BMP signaling in particular is disrupted in the germline of patients with familial juvenile polyposis, an autosomal dominant syndrome with a 12-fold increase in risk for colon cancer over the general population. Researchers are actively investigating cellular and signaling mechanisms by which BMP and activin may initiate and drive proliferation and allow cells to exhibit metastatic properties.     

Bone morphogenetic protein (BMP)-2 induces apoptosis in human myeloma cells

BMPs (bone morphogenetic proteins), members of the transforming growth factor (TGF)-beta superfamily, are a group of related proteins which are capable of inducing the formation of cartilage and bone, but are now regarded as multifunctional cytokines. However, little is known about their role in hematopoiesis. Recently, we found a novel function of BMPs to hematopoietic cells in that BMP-2 induces apoptosis not only in human myeloma cell lines, but also in primary samples from patients with multiple myeloma in vitro. BMP-2 caused cell cycle arrest in the G1 phase which was associated with accumulation of p21CIP1/WAF1 and p27KIP1, and the subsequent apoptosis of myeloma cells. Further analysis showed that BMP-2 induced down-regulation of Bcl-X(L) through the inactivation of STAT3, resulting in the induction of apoptosis in myeloma cells. We conclude that BMP-2 may have the potential to be one of the novel therapeutic agents for treatment in patients with multiple myeloma because of the beneficial effects on both myeloma cells and bone diseases. In this review, we summarize data concerning BMPs and BMP-2-induced apoptosis of myeloma cells including our own recent experimental data.