Block Tumor Metastasis Research Articles

IL4 Receptor-Targeted Proapoptotic Peptide Blocks Tumor Growth and Metastasis by Enhancing Antitumor Immunity.

Cellular cross-talk between tumors and M2-polarized tumor-associated macrophages (TAM) favors tumor progression. Upregulation of IL4 receptor (IL4R) is observed in diverse tumors and TAMs. We tested whether an IL4R-targeted proapoptotic peptide could inhibit tumor progression. The IL4R-binding peptide (IL4RPep-1) preferentially bound to IL4R-expressing tumor cells and M2-polarized macrophages both in vitro and in 4T1 breast tumors in vivo To selectively kill IL4R-expressing cells, we designed an IL4R-targeted proapoptotic peptide, IL4RPep-1-K, by adding the proapoptotic peptide (KLAKLAK)2 to the end of IL4RPep-1. IL4RPep-1-K exerted selective cytotoxicity against diverse IL4R-expressing tumor cells and M2-polarized macrophages. Systemic administration of IL4RPep-1-K inhibited tumor growth and metastasis in 4T1 breast tumor-bearing mice. Interestingly, IL4RPep-1-K treatment increased the number of activated cytotoxic CD8+ T cells while reducing the numbers of immunosuppressive regulatory T cells and M2-polarized TAMs. No significant systemic side effects were observed. These results suggest that IL4R-targeted proapoptotic peptide has potential for treating diverse IL4R-expressing cancers. Mol Cancer Ther; 16(12); 2803-16. ©2017 AACR.

Abstract 1892: Small molecule NSC59984 prevents cancer cell migration and invasion

Abstract Tumor metastasis is one of the main mechanisms leading to mortality of cancer patients. Searching for new therapeutic strategies to prevent tumor metastasis is one of the anti-tumor approaches in cancer therapy. Cell migration and invasion are crucial initial steps in the complex process and progression of tumor metastasis. Mutant p53 has been known as an important factor associated to cancer cell migration. Therefore, targeting mutant p53 is a potential strategy to avoid tumor metastatic spread. We previously reported an anti-tumor small molecule, NSC59984 which degrades mutant p53 and restores p53 pathway via activation of p73. Here we demonstrate that NSC59984 inhibits cancer cell migration and invasion. Treatment with NSC59984 partially attenuates cell migration in various cancer cells based on the scratch assay and Boyden chamber assay. The effect of NSC59984 on cell migration is partially blocked by knockdown of p73, a member of the p53 family, suggesting that restoration of p53 pathway signaling via p73 is required for NSC59984-inhibition of cell migration in cancer cells. We found that NSC59984 induces ERK2-dependent p53 restoration and mutant p53 degradation. To examine the role of ERK2 in the cell migration, ERK2 signaling is blocked by U0126 treatment in cancer cells. The effect of NSC59984 on cancer cell migration is partially inhibited by U0126 treatment, suggesting that NSC59984 inhibits cancer cell migration partially dependent on ERK1/2 pathway signaling in cancer cells. In addition, the gelatin degradation assay shows that NSC59984 inhibits cancer cell invasion. Consistent to the in vitro assays, NSC59984 decreases tumor invasion of xenograft tumors as compared to the xenograft tumors treated with DMSO as control. Our results, taken together, suggest that NSC59984 not only suppresses tumor growth, but also inhibits cancer cell migration and invasion. Our findings provide the potential administration of p53-restoring compound NSC59984 in cancer therapy by blocking tumor metastasis. Citation Format: Shengliang Zhang, Jessica Wagner, Lanlan Zhou, Wafik S. El-Deiry. Small molecule NSC59984 prevents cancer cell migration and invasion [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1892. doi:10.1158/1538-7445.AM2017-1892

FOXO3a promotes gastric cancer cell migration and invasion through the induction of cathepsin L.

Forkhead box O3A (FOXO3a) is an important transcription factor involved in various human cancers. However, the role of FOXO3a in regulating the invasion and metastasis of gastric cancer cells has not been clarified. Here, we report that FOXO3a overexpression promoted migration and invasion of gastric cancer cells by upregulating cathepsin L. FOXO3a knockdown suppressed migration and invasion and also downregulated cathepsin L expression in gastric cancer cells. Silencing cathepsin L in these cells suppressed FOXO3a overexpression-induced cell migration and invasion. Mechanistic studies revealed that FOXO3a increased cathepsin L promoter activation, and cathepsin L overexpression repressed E-cadherin expression, causing gastric cancer cells to undergo epithelial-mesenchymal transition (EMT). Our data reveal a previously unexplored function of FOXO3a in gastric cancer invasion by regulating proteins involved in extracellular matrix (ECM) degradation and EMT. We suggest that FOXO3a may be of prognostic value and a potential therapeutic target in blocking tumor metastasis.

Semaphorin 7a exerts pleiotropic effects to promote breast tumor progression.

Understanding what drives breast tumor progression is of utmost importance for blocking tumor metastasis; we have identified that semaphorin 7a is a potent driver of ductal carcinoma in situ (DCIS) progression. Semaphorin 7a is a GPI membrane anchored protein that promotes attachment and spreading in multiple cell types. Here we show that increased expression of SEMA7A occurs in a large percentage of breast cancers and is associated with decreased overall and distant metastasis free survival. In both in vitro and in vivo models, shRNA mediated silencing of SEMA7A reveals roles for semaphorin 7a in the promotion of DCIS growth, motility, and invasion as well as lymphangiogenesis in the tumor microenvironment. Our studies also uncover a relationship between COX-2 and semaphorin 7a expression and suggest that semaphorin 7a promotes tumor cell invasion on collagen and lymphangiogenesis via activation of β1-integrin receptor. Our results suggest that semaphorin 7a, may be novel target for blocking breast tumor progression.

Abstract PR10: Silencing of semaphorin 7a attenuates breast tumor progression

Abstract Determining what drives conversion of non-lethal to lethal breast cancers is of utmost importance for understanding and blocking tumor metastasis. We have identified semaphorin 7a (Sem7a) as a potent driver of human breast cancer progression, suggesting it may represent a novel target to inhibit metastasis. Sem7a is a GPI membrane anchored protein that promotes attachment and spreading in multiple cell types1,2; previous reports have identified a role for Sem7a in mouse mammary tumorigenesis, including promotion of tumor growth and EMT, as well as induction of angiogenic cytokine production by macrophages and metastatic outgrowth in the lung3-5. However, Sem7a has not been investigated in human breast tumors, so we utilized publicly available microarray datasets and found that SEMA7A gene expression is increased in ~45% of all breast cancers. Further, we found SEMA7A upregulation was associated with poor prognosis, which is consistent with a role in metastasis. Specifically, breast cancer patients with high expression of SEMA7A are at risk for early recurrence and have decreased overall and distant metastasis-free survival rates. We used in vitro and in vivo approaches to assess the role of SEM7a in human breast tumor progression. In vivo, we show that shRNA mediated silencing of Sem7a significantly slows tumor growth, delays tumor progression from in situ to locally invasive disease, and decreases tumor associated lymphangiogenesis. Furthermore, having previously shown that collagen I and COX-2 drive tumor progression in our breast cancer models6,7, we identified a relationship between COX-2 and Sem7a expression at the mRNA and protein levels. Finally, using three- dimensional spheroid and tube formation assays, we show that semaphorin 7a promotes tumor cell invasion on collagen, and lymphangiogenesis, via activation of the β1-integrin receptor. Our results indicate that Sem7a may be novel target for blocking multiple aspects of breast tumor progression that lead to metastasis.

5-(Bis(3-(2-hydroxyethyl)-1H-indol-2-yl)methyl)-2-hydroxybenzoic acid (BHIMHA): showing a strategy of designing drug to block lung metastasis of tumors.

Early metastasis is still the most recalcitrant factor in the treatment of lung cancer patients. By analyzing the structures and comparing the docking scores of the known pharmacophores, the authors of this paper designed 5-(bis(3-(2-hydroxyethyl)-1H-indol-2-yl)methyl)-2-hydroxybenzoic acid (BHIMHA) as a promising lead compound to develop metastasis inhibitors. In vitro 5, 10, and 20 µM of BHIMHA concentration dependently inhibited the migration and invasion of A549 cells. In vivo 0.4, 2.0, and 8.9 µmol/kg of BHIMHA dose dependently inhibited the metastasis of LLC (Lewis Lung Carcinoma) toward lung. In vivo, 2 µmol/kg of BHIMHA showed additional actions of slowing the growth of the primary tumor of C57BL/6 mice and S180 mice as well as inhibiting xylene-induced ear edema of the mice. Therefore, BHIMHA simultaneously blocked tumor metastasis toward lung, slowed the primary tumor growth, and limited the inflammation. These pharmacological actions were correlated with the inhibition of PKCα and NF-κB expression.

Abstract B15: Semaphorin 7a exerts pleiotropic effects to promote breast tumor progression

Abstract Understanding what drives breast tumor progression is of utmost importance for blocking tumor metastasis. We have identified that semaphorin 7a is a potent driver of breast tumor progression. Semaphorin 7a is a GPI membrane anchored protein that promotes attachment and spreading in multiple cell types. We observe that increased expression of SEMA7A occurs in ~45%human breast cancers and its upregulation is associated with decreased overall and distant metastasis free survival. In both in vitro and in vivo models, shRNA mediated silencing reveals roles for semaphorin 7a in the promotion of breast cancer cell growth, motility, and invasion as well as in lymphangiogenesis. Our studies also uncover a relationship between COX-2 and semaphorin 7a expression, and suggest that semaphorin 7a promotes tumor cell invasion on collagen and lymphangiogenesis via activation of β1-integrin receptor. Our results suggest that semaphorin 7a, may be novel target for blocking breast tumor progression. Citation Format: Sarah Black, Andrew Nelson, Natalia Gurule, Bernard Futscher, Traci R. Lyons. Semaphorin 7a exerts pleiotropic effects to promote breast tumor progression. [abstract]. In: Proceedings of the AACR Special Conference on Advances in Breast Cancer Research; Oct 17-20, 2015; Bellevue, WA. Philadelphia (PA): AACR; Mol Cancer Res 2016;14(2_Suppl):Abstract nr B15.

Monocytes block tumor access to the lung

Cancer Immunology![Figure][1] Tumor cells (red) in mouse lungs recruit patrolling monocytes (green) PHOTO: RICHARD N. HANNA, LA JOLLA INSTITUTE FOR ALLERGY AND IMMUNOLOGY Metastatic cancer is especially hard to treat. In order to find potential new therapeutic targets, scientists are trying to understand the cellular events that promote or prevent metastasis. Hanna et al. now report a role for patrolling monocytes in blocking tumor metastasis to the lungs in mice. Tumors in mice engineered to lack patrolling monocytes showed increased metastasis to the lung but not to other tissues. Patrolling monocytes resided in the microvasculature of the lung, where they engulfed tumor material, which may explain how these cells prevent tumors from colonizing the lung. Science , this issue p. [985][2] [1]: pending:yes [2]: /lookup/doi/10.1126/science.aac9407

Conserved E2F mediated metastasis in mouse models of breast cancer and HER2 positive patients.

To improve breast cancer patient outcome work must be done to understand and block tumor metastasis. This study leverages bioinformatics techniques and traditional genetic screens to create a novel method of discovering potential contributors of tumor progression with a focus on tumor metastasis. A database of 1172 of expression data from a variety of mouse models of breast cancer was assembled and queried using previously defined oncogenic activity signatures. This analysis revealed high activity of the E2F family of transcription factors in the MMTV-Neu mouse model. A genetic cross of MMTV-Neu mice into an E2F1 null, E2F2 null, or E2F3 heterozygous background revealed significant changes in tumor progression specifically reductions in tumor latency and metastasis with E2F1 or E2F2 loss. These findings were found to be conserved in human HER2 positive patients. Patients with high E2F1 activity were shown to have worse outcomes such as relapse free survival and distant metastasis free survival. This study shows conserved mechanisms of tumor progression in human breast cancer subtypes and analogous mouse models and underlies the importance of increased research into the characterization of and comparisons between mouse and human tumors to identify which mouse models resemble each subtype of human breast cancer.

Patrolling monocytes control tumor metastasis to the lung.

The immune system plays an important role in regulating tumor growth and metastasis. Classical monocytes promote tumorigenesis and cancer metastasis, but how nonclassical "patrolling" monocytes (PMo) interact with tumors is unknown. Here we show that PMo are enriched in the microvasculature of the lung and reduce tumor metastasis to lung in multiple mouse metastatic tumor models. Nr4a1-deficient mice, which specifically lack PMo, showed increased lung metastasis in vivo. Transfer of Nr4a1-proficient PMo into Nr4a1-deficient mice prevented tumor invasion in the lung. PMo established early interactions with metastasizing tumor cells, scavenged tumor material from the lung vasculature, and promoted natural killer cell recruitment and activation. Thus, PMo contribute to cancer immunosurveillance and may be targets for cancer immunotherapy.

Targeting IL-17B-IL-17RB signaling with an anti-IL-17RB antibody blocks pancreatic cancer metastasis by silencing multiple chemokines.

Pancreatic cancer has an extremely high mortality rate due to its aggressive metastatic nature. Resolving the underlying mechanisms will be crucial for treatment. Here, we found that overexpression of IL-17B receptor (IL-17RB) strongly correlated with postoperative metastasis and inversely correlated with progression-free survival in pancreatic cancer patients. Consistently, results from ex vivo experiments further validated that IL-17RB and its ligand, IL-17B, plays an essential role in pancreatic cancer metastasis and malignancy. Signals from IL-17B-IL-17RB activated CCL20/CXCL1/IL-8/TFF1 chemokine expressions via the ERK1/2 pathway to promote cancer cell invasion, macrophage and endothelial cell recruitment at primary sites, and cancer cell survival at distant organs. Treatment with a newly derived monoclonal antibody against IL-17RB blocked tumor metastasis and promoted survival in a mouse xenograft model. These findings not only illustrate a key mechanism underlying the highly aggressive characteristics of pancreatic cancer but also provide a practical approach to tackle this disease.

Discovery of a Series of Thiazole Derivatives as Novel Inhibitors of Metastatic Cancer Cell Migration and Invasion

Effective inhibitors of cancer cell migration and invasion can potentially lead to clinical applications as therapy to block tumor metastasis, the primary cause of death in cancer patients. To this end we have designed and synthesized a series of thiazole derivatives that showed potent efficacy against cell migration and invasion in metastatic cancer cells. The most effective compound, 5k, was found to have an IC50 value of 176 nM in the dose-dependent transwell migration assays in MDA-MB-231cells. At the dose of 10 μM, 5k also blocked about 80% of migration in HeLa and A549 cells and 60% of invasion of MDA-MB-231 cells. Importantly, the majority of the derivatives exhibited no apparent cytotoxicity in the clonogenic assays. The low to negligible inhibition of cell proliferation is a desirable property of these anti-migration derivatives because they hold promise of low toxicity to healthy cells as potential therapeutic agents. Mechanistic studies analyzing the actin cytoskeleton by microscopy demonstrate that compound 5k substantially reduced cellular f-actin, and prevented localization of fascin to actin-rich membrane protrusions. These results suggest that the anti-migration activity may result from impaired actin structures in protrusions that are necessary to drive migration.

A cell-based fascin bioassay identifies compounds with potential anti-metastasis or cognition-enhancing functions

SUMMARY The actin-bundling protein fascin is a key mediator of tumor invasion and metastasis and its activity drives filopodia formation, cell-shape changes and cell migration. Small-molecule inhibitors of fascin block tumor metastasis in animal models. Conversely, fascin deficiency might underlie the pathogenesis of some developmental brain disorders. To identify fascin-pathway modulators we devised a cell-based assay for fascin function and used it in a bidirectional drug screen. The screen utilized cultured fascin-deficient mutant Drosophila neurons, whose neurite arbors manifest the 'filagree' phenotype. Taking a repurposing approach, we screened a library of 1040 known compounds, many of them FDA-approved drugs, for filagree modifiers. Based on scaffold distribution, molecular-fingerprint similarities, and chemical-space distribution, this library has high structural diversity, supporting its utility as a screening tool. We identified 34 fascin-pathway blockers (with potential anti-metastasis activity) and 48 fascin- pathway enhancers (with potential cognitive-enhancer activity). The structural diversity of the active compounds suggests multiple molecular targets. Comparisons of active and inactive compounds provided preliminary structure-activity relationship information. The screen also revealed diverse neurotoxic effects of other drugs, notably the 'beads-on-a-string' defect, which is induced solely by statins. Statin-induced neurotoxicity is enhanced by fascin deficiency. In summary, we provide evidence that primary neuron culture using a genetic model organism can be valuable for early-stage drug discovery and developmental neurotoxicity testing. Furthermore, we propose that, given an appropriate assay for target-pathway function, bidirectional screening for brain-development disorders and invasive cancers represents an efficient, multipurpose strategy for drug discovery.

MicroRNA-10a targets CHL1 and promotes cell growth, migration and invasion in human cervical cancer cells

MicroRNAs (miRNAs) play an important role in cancer initiation, progression and metastasis by regulating their target genes. Here, we found microRNA-10a (miR-10a) is upregulated in human cervical cancer and promotes the colony formation activity, migration and invasion of HeLa and C33A cells. Subsequently, CHL1 is confirmed as a target of miR-10a and is negatively regulated by miR-10a at mRNA and protein levels. Furthermore, knockdown of CHL1 expression results in increased colony formation activity, migration and invasion. Finally, overexpression of CHL1 lacked the 3′UTR abolished the effects of miR-10a. Our results may provide a strategy for blocking tumor metastasis.

Antitumor efficacy of viable tumor vaccine modified by heterogenetic ESAT-6 antigen and cytokine IL-21 in melanomatous mouse

The goal of this study was to investigate whether glycosylphosphatidylinositol (GPI)-anchored 6kDa early secreted antigenic target (ESAT-6) and IL-21-producing B16F10/ESAT-6-GPI-IL-21 viable vaccine would induce antitumor efficacy. Mice were immunized with B16F10/ESAT-6-GPI-IL-21 vaccine and challenged by B16F10 cells 2weeks later. Antitumor efficacy and mechanisms of the vaccine were analyzed. Vaccination with the viable B16F10/ESAT-6-GPI-IL-21 vaccine resulted in an increase of IFN-γ level and the CD8(+)CTL cytotoxicity, a decrease in TGF-β generation and increase in the expression of miR-200c that serves as melanoma suppressor by directly targeting zinc-finger E-box binding homeobox 1 to inhibit epithelial-mesenchymal transition and block tumor metastasis. The vaccine significantly inhibited the melanoma growth, reduced the lung melanoma nodules, and prolonged the mouse survival compared with the controls. These findings highlighted IL-21 as an immune adjuvant in an engineered viable tumor vaccine to reinforce heterogenetic antigen ESAT-6 immune tolerance break to induce powerful antitumor efficacy in mice.

Heparin-induced Leukocytosis Requires 6-O-Sulfation and Is Caused by Blockade of Selectin- and CXCL12 Protein-mediated Leukocyte Trafficking in Mice

Leukocytosis refers to an increase in leukocyte count above the normal range in the blood and is a common laboratory finding in patients. In many cases, the mechanisms underlying leukocytosis are not known. In this study, we examined the effects, the structural determinants, and the underlying mechanisms of heparin-induced leukocytosis, a side effect occurring in 0.44% of patients receiving heparin. We observed that heparin induced both lymphocytosis and neutrophilia, and the effects required heparin to be 6-O-sulfated but did not require its anticoagulant activity. Cell mobilization studies revealed that the lymphocytosis was attributable to a combination of blockage of lymphocyte homing and the release of thymocytes from the thymus, whereas the neutrophilia was caused primarily by neutrophil release from the bone marrow and demargination in the vasculature. Mechanistic studies revealed that heparin inhibits L- and P-selectin, as well as the chemokine CXCL12, leading to leukocytosis. Heparin is known to require 6-O-sulfate to inhibit L- and P-selectin function, and in this study we observed that 6-O-sulfate is required for its interaction with CXCL12. We conclude that heparin-induced leukocytosis requires glucosamine 6-O-sulfation and is caused by blockade of L-selectin-, P-selectin-, and CXCL12-mediated leukocyte trafficking.

A cell-based fascin bioassay identifies compounds with potential anti-metastasis or cognition-enhancing functions

SUMMARYThe actin-bundling protein fascin is a key mediator of tumor invasion and metastasis and its activity drives filopodia formation, cell-shape changes and cell migration. Small-molecule inhibitors of fascin block tumor metastasis in animal models. Conversely, fascin deficiency might underlie the pathogenesis of some developmental brain disorders. To identify fascin-pathway modulators we devised a cell-based assay for fascin function and used it in a bidirectional drug screen. The screen utilized cultured fascin-deficient mutant Drosophila neurons, whose neurite arbors manifest the ‘filagree’ phenotype. Taking a repurposing approach, we screened a library of 1040 known compounds, many of them FDA-approved drugs, for filagree modifiers. Based on scaffold distribution, molecular-fingerprint similarities, and chemical-space distribution, this library has high structural diversity, supporting its utility as a screening tool. We identified 34 fascin-pathway blockers (with potential anti-metastasis activity) and 48 fascin-pathway enhancers (with potential cognitive-enhancer activity). The structural diversity of the active compounds suggests multiple molecular targets. Comparisons of active and inactive compounds provided preliminary structure-activity relationship information. The screen also revealed diverse neurotoxic effects of other drugs, notably the ‘beads-on-a-string’ defect, which is induced solely by statins. Statin-induced neurotoxicity is enhanced by fascin deficiency. In summary, we provide evidence that primary neuron culture using a genetic model organism can be valuable for early-stage drug discovery and developmental neurotoxicity testing. Furthermore, we propose that, given an appropriate assay for target-pathway function, bidirectional screening for brain-development disorders and invasive cancers represents an efficient, multipurpose strategy for drug discovery.

Norcantharidin, a protective therapeutic agent in renal tubulointerstitial fibrosis

Progressive renal tubulointerstitial fibrosis is a common final pathway of nearly all forms of chronic kidney disease. Many efforts have been done to arrest or prevent renal tubulointerstitial fibrosis but with little progress. Nowadays, few therapeutic agents are available in clinical use. Norcantharidin (NCTD) is of great benefit in anticancer treatment, by inducing cell apoptosis, inhibiting cell proliferation, in addition, blocking tumor metastasis and angiogenesis in cancer, whereas little attention is given to its relationship with other diseases. Our recent studies demonstrated that NCTD was protective against renal tubulointerstitial fibrosis both in vivo and in vitro. The underlying mechanisms may include modulation of TGF-β1/Smad signal cascade, inhibition of protein serine/threonine phosphatases (PPP) as well as NF-κB. NCTD may be a promising therapeutic agent for renal tubulointerstitial fibrosis. In the present article, we will review the action of NCTD in renal tubulointerstitial fibrosis and discuss its possible mechanisms.

Roles of CUB domain‐containing protein 1 signaling in cancer invasion and metastasis

Tumor metastasis is a complex multistep process by which cells from the primary tumor invade tissues, move through the vasculature, settle at distant sites and eventually grow to form secondary tumors. Altered tyrosine phosphorylation signals in cancer cells contribute to a number of aberrant characteristics involved in tumor invasion and metastasis. CUB domain-containing protein 1 (CDCP1) is a substrate of Src family kinases and has been shown to regulate anoikis resistance, migration and matrix degradation during tumor invasion and metastasis in a tyrosine phosphorylation-dependent manner. Knockdown of CDCP1 blocks tumor metastasis or peritoneal dissemination in vivo, without significantly affecting cell proliferation. Moreover, expression levels of CDCP1 are of prognostic value in several cancers. Here, we summarize the studies on CDCP1, focusing on structure and signal transduction, to gain insight into its role in cancer progression. Understanding the signaling pathways regulated by CDCP1 could help establish novel therapeutic strategies against the progression of cancer.

Cobalt chloride에 의해 유도되는 상피-중간엽 이행에서의 국소부착 단백질의 인산화의 역할 규명

Hypoxia is a common condition found in a wide range of solid tumors and is often associated with metastasis and poor clinical outcomes. In the present study, we found that HIF- was induced by cobalt chloride (500 ) treatment on human lung cancer cells, A549 and H460, for 24 hr. However, cobalt chloride (500 ) did not affect cell proliferation of A549 and H460 in 48 hr. Cobalt chloride (500 ) additionally induced epithelial-to-mesenchymal-like transition (EMT) such as reduced E-cadherin expression and increased -SMA expression. These results were confirmed by immunofluorecence experiment in H460 cells. E-cadherin was localized on the outer cell membrane. However, when the cells were treated with 500 cobalt chloride for 24 hr, diffuse E-cadherin staining was observed, characteristic of a migratory mesenchymal phenotype. We also found that cobalt chloride induced integrin expression and FAK phosphorylation in human lung cancer cells using western blotting and FACS anlaysis. Our data suggest that integrin -induced FAK phosphorylation may be developed into target molecules for blocking tumor metastasis.