IL-1 stimulates growth and metastasis of human cancer xenografts in nude mice

Interleukin 1 (IL-1) is a pluripotent cytokine that promotes inflammation, angiogenesis, tumor growth andmetastasis in experimental models; its presence in some human cancers is associated with tumor progression. Alex-ander et al. recently reported that inhibition of IL-1 by its receptor antagonist (IL-1Ra) retarded growth of IL-1-ex-pressing human cancer xenografts in nude mice (Clin Cancer Res 2006, 12:1088 ~1096). IL-1 mRNA and pro-tein levels were determined in clinical tumor samples…     

Ligand-independent activation of c-Met by fibronectin and α(5)β(1)-integrin regulates ovarian cancer invasion and metastasis

The role of the fibronectin receptor, α(5)β(1)-integrin, as an adhesion receptor and in angiogenesis is well established. However, its role in cancer cell invasion and metastasis is less clear. We describe a novel mechanism by which fibronectin regulates ovarian cancer cell signaling and promotes metastasis. Fibronectin binding to α(5)β(1)-integrin led to a direct association of α(5)-integrin with the receptor tyrosine kinase, c-Met, activating it in a hepatocyte growth factor/scatter factor (HGF/SF) independent manner. Subsequently, c-Met associated with Src, and activated Src and focal adhesion kinase (FAK). Inhibition of α(5)β(1)-integrin decreased the phosphorylation of c-Met, FAK and Src, both in vitro and in vivo. Independent activation of c-Met by its native ligand, HGF/SF, or overexpression of a constitutively active FAK in HeyA8 cells could overcome the effect of α(5)β(1)-integrin inhibition on tumor cell invasion, indicating that α(5)β(1)-integrin is upstream of c-Met, Src and FAK. Inhibition of α(5)β(1)-integrin on cancer cells in two xenograft models of ovarian cancer metastasis resulted in a significant decrease of tumor burden, which was independent of the effect of α(5)β(1)-integrin on angiogenesis. These data suggest that fibronectin promotes ovarian cancer invasion and metastasis through an α(5)β(1)-integrin/c-Met/FAK/Src-dependent signaling pathway, transducing signals through c-Met in an HGF/SF-independent manner.     

The TGF-β/Smad2/3 signaling pathway is involved in Musashi2-induced invasion and metastasis of colorectal cancer

To identify Musashi2 as an effective biomarker regulated by the TGF-β/Smad_2/3 signaling pathway for the precise diagnosis and treatment of colorectal cancer (CRC) through bioinformatic tools and experimental verification. The Cancer Genome Atlas, Timer, and Kaplan−Meier analyses were performed to clarify the expression of Musashi2 and its influence on the prognosis of CRC. Transforming growth factor beta 1 (TGF-β1) was used to activate the TGF-β/Smad_2/3 signaling pathway to identify whether it could regulate the expression and function of Musashi2. Western blot analysis and quantitative PCR analyses were conducted to verify the expression of Musashi2. Cell counting kit-8 (CCK8), EdU, wound healing, and Transwell assays were conducted to reveal the role of Musashi2 in the proliferation, migration, and invasion of CRC. Musashi2 was upregulated in CRC and promoted proliferation and metastasis. TGF-β1 increased the expression of Musashi2, while the antagonist inducer of type II TGF-β receptor degradation-1 (ITD-1) decreased the expression. CCK8 and EdU assays demonstrated that inhibition of Musashi2 or use of ITD-1 lowered proliferation ability. The Transwell and wound healing assays showed that the migration and invasion abilities of CRC cells could be regulated by Musashi2. The above functions could be enhanced by TGF-β1 by activating the TGF-β/Smad_2/3 signaling pathway and reversed by ITD-1. A positive correlation was found between Musashi2 and the TGF-β/Smad_2/3 signaling pathway. TGF-β1 activates the TGF-β/Smad_2/3 pathway to stimulate the expression of Musashi2, which promotes the progression of CRC. Musashi2 might become a target gene for the development of new antitumor drugs.     

The TGF-β/Smad pathway induces breast cancer cell invasion through the up-regulation of matrix metalloproteinase 2 and 9 in a spheroid invasion model system

Transforming growth factor-β (TGF-β) has opposing roles in breast cancer progression by acting as a tumor suppressor in the initial phase, but stimulating invasion and metastasis at later stages. In contrast to the mechanisms by which TGF-β induces growth arrest, the pathways that mediate tumor invasion are not well understood. Here, we describe a TGF-β-dependent invasion assay system consisting of spheroids of MCF10A1 normal breast epithelial cells (M1) and RAS-transformed (pre-)malignant derivatives (M2 and M4) embedded in collagen gels. Both basal and TGF-β-induced invasion of these cell lines was found to correlate with their tumorigenic potential; M4 showing the most aggressive behavior and M1 showing the least. Basal invasion was strongly inhibited by the TGF-β receptor kinase inhibitor SB-431542, indicating the involvement of autocrine TGF-β or TGF-β-like activity. TGF-β-induced invasion in premalignant M2 and highly malignant M4 cells was also inhibited upon specific knockdown of Smad3 or Smad4. Interestingly, both a broad spectrum matrix metalloproteinase (MMP) inhibitor and a selective MMP2 and MMP9 inhibitor mitigated TGF-β-induced invasion of M4 cells, while leaving basal invasion intact. In line with this, TGF-β was found to strongly induce MMP2 and MMP9 expression in a Smad3- and Smad4-dependent manner. This collagen-embedded spheroid system therefore offers a valuable screening model for TGF-β/Smad- and MMP2- and MMP9-dependent breast cancer invasion.     

Integrin β1 mediates epithelial growth factor-induced invasion in human ovarian cancer cells

Integrins function as cell-extracellular matrix adhesion proteins and have been implicated in tumor progression. In ovarian tumors, elevated integrin β1 expression correlates with high clinical stage and poor patient survival. In this study, we report that EGF treatment up-regulated integrin β1 mRNA and protein levels in ovarian cancer cells. Moreover, pharmacological inhibition of MEK totally abolished EGF-induced integrin β1 up-regulation and cell invasion suggesting that MAPK/ERK signaling is required for EGF-induced integrin β1 up-regulation and cell invasion. Furthermore, we found that knockdown of integrin β1 expression reduced the intrinsic invasiveness of ovarian cancer cells and the EGF-induced cell invasion. Finally, we found that overexpression of integrin β1 was sufficient to promote ovarian cancer cell invasion. This study demonstrates that integrin β1 mediates EGF-induced cell invasion in ovarian cancer.     

γ-tocotrienol inhibits angiogenesis-dependent growth of human hepatocellular carcinoma through abrogation of AKT/mTOR pathway in an orthotopic mouse model

Angiogenesis is one of the key hallmarks of cancer. In this study, we investigated whether γ-tocotrienol can abrogate angiogenesis-mediated tumor growth in hepatocellular carcinoma (HCC) and if so, through what molecular mechanisms. We observed that γ-tocotrienol inhibited vascular endothelial growth factor (VEGF)-induced migration, invasion, tube formation and viability of HUVECs in vitro. Moreover, γ-tocotrienol reduced the number of capillary sprouts from matrigel embedded rat thoracic aortic ring in a dose-dependent manner. Also, in chick chorioallantoic membrane assay, γ-tocotrienol significantly reduced the blood vessels formation. We further noticed that γ-tocotrienol blocked angiogenesis in an in vivo matrigel plug assay. Furthermore, γ-tocotrienol inhibited VEGF-induced autophosphorylation of VEGFR2 in HUVECs and also suppressed the constitutive activation of AKT/mammalian target of rapamycin (mTOR) signal transduction cascades in HUVECs as well as in HCC cells. Interestingly, γ-tocotrienol was also found to significantly reduce the tumor growth in an orthotopic HCC mouse model and inhibit tumor-induced angiogenesis in HCC patient xenografts through the suppression of various biomarkers of proliferation and angiogenesis. Taken together, our findings strongly suggest that γ-tocotrienol might be a promising anti-angiogenic drug with significant antitumor activity in HCC.     

High expression of IL-13 receptor α2 in colorectal cancer is associated with invasion, liver metastasis, and poor prognosis

Autocrine secretion of cytokines by metastatic colorectal cancer cells and their role during invasion and liver homing has been poorly characterized. In this study, we used cytokine arrays to analyze the secretomes of poorly and highly metastatic colorectal cancer cells. Compared with poorly metastatic cancer cells, highly metastatic cells expressed increased levels of the immunosuppressive cytokines interleukin (IL)-4 and IL-13 in addition to increased surface expression of the high affinity IL-13 receptor IL-13Rα2, suggesting that IL-13Rα2 mediates IL-13 effects in colorectal cancer cells. Silencing of IL-13Rα2 in highly metastatic cells led to a decrease in adhesion capacity in vitro and a reduction in liver homing and increased survival in vivo, revealing a role for this receptor in cell adhesion, migration, invasion, and metastatic colonization. In support of this, IL-13 signaling activated the oncogenic signaling molecules phosphoinositide 3-kinase, AKT, and SRC in highly metastatic cells. Clinically, high expression of IL-13Rα2 was associated with later stages of disease progression and poor outcome in patients with colorectal cancer. Our findings therefore support a critical role for IL-13Rα2 expression in colon cancer invasion and metastasis.     

Inhibition of the Rho/ROCK pathway enhances the efficacy of cisplatin through the blockage of hypoxia-inducible factor-1α in human ovarian cancer cells

Rho, a Ras-related small GTPase, and Rho-associated coiled coil-containing protein kinase (Rho kinase, ROCK1 and ROCK2) are key regulators of focal adhesion, actomyosin contraction, and thus cell motility. Rho/ROCK kinases also play roles in proliferation, differentiation, apoptosis and oncogenic transformation. In the present study, we have shown that Rho/ROCK pathway inhibition by fasudil, an orally administered inhibitor of Rho kinases, enhanced cisplatin-induced growth inhibition and apoptosis in human ovarian cancer cell lines. Fasudil inhibited hypoxia inducible factor (HIF)-1α protein expression. Knockdown of RhoA, ROCK1 or ROCK2 also attenuated the expression of HIF-1α. Furthermore, knockdown of HIF-1α using small interfering RNA enhanced cisplatin-induced growth inhibition and apoptosis as did inhibition of the Rho/ROCK pathway by fasudil, the Rho/ROCK inhibitor Y27632, or by Rho/ROCK knockdown. Therefore, the Rho/ROCK pathway may modulate HIF-1α signal transduction and blockade of Rho/ROCK enhances the efficacy of cisplatin by inhibiting HIF-1α in ovarian cancer cells. Our findings suggested that the Rho/ROCK pathway may be a new target for molecular targeting therapies against ovarian cancer.     

Recurrence and cancer-specific survival according to the expression of IL-4Rα and IL-13Rα1 in patients with oral cavity cancer

BackgroundInterleukin-4 (IL-4) and interleukin-13 (IL-13) are anti-inflammatory and immunomodulatory cytokines that play crucial roles in cancer progression. However, the clinical significance of the expression of these cytokines and their receptors (IL-4R) in oral cavity squamous cell carcinoma (OSCC) is unknown. Therefore, we evaluated the expression of IL-4R in OSCC specimens by immunohistochemistry (IHC) and analysed its relationship to recurrence and survival.MethodsA total of 186 patients with OSCC were enrolled, and the expression of IL-4Rα and IL-13Rα1 on their primary tumour specimens was evaluated by IHC and correlated to clinicopathologic parameters, recurrence and survival.FindingsHigh expression of IL-4Rα and IL-13Rα1 was observed in 60 (32.3%) and 165 (88.7%) patients, respectively. IL-4Rα expression was inversely correlated with parameters reflecting primary tumour burden, including tumour size, tumour stage and depth of invasion at the initial diagnosis (P < 0.05). High expression of IL-4Rα also correlated with a greater risk of recurrence (P = 0.002), but was unrelated to cancer-specific survival (CSS, P = 0.118). Conversely, high IL-13Rα1 expression correlated with reduced recurrence (P < 0.001) and increased CSS (P < 0.001) in OSCC patients.InterpretationsHigh expression of IL-4Rα correlated with increased recurrence, while high IL-13Rα1 expression had an inverse relationship to recurrence and CSS in OSCC patients.     

Diallyl trisulfide alleviates chemotherapy sensitivity of ovarian cancer via the AMPK/SIRT1/PGC1α pathway

Platinum-based chemotherapy promotes drug resistance in ovarian cancer. We investigated the antichemoresistance characteristics of diallyl trisulfide (DATS) in cisplatin-resistant ovarian cancer cells, in vitro and in vivo. Previous preclinical studies have revealed that DATS regulates distinct hallmark cancer-signaling pathways. The cell cycle pathway is the most investigated signaling pathway in DATS. Additionally, post-DATS treatment has been found to promote proapoptotic capacity through the regulation of intrinsic and extrinsic apoptotic pathway components. In the present study, we found that treating cisplatin-sensitive and cisplatin-resistant ovarian cell lines with DATS inhibited their proliferation and reduced their IC_50. It induced cell apoptosis and promoted oxidative phosphorylation through the regulation of the AMPK/SIRT1/PGC1α pathway, OXPHOS, and enhanced chemotherapy sensitivity. DATS treatment alleviated glutamine consumption in cisplatin-resistant cells. Our findings highlight the role of DATS in overcoming drug resistance in ovarian cancer in vitro and in vivo. In addition, we elucidated the role of the AMPK/SIRT1/PGC1α signaling pathway as a potential target for the treatment of drug-resistant ovarian cancer.     

Tumor-associated macrophages regulate gastric cancer cell invasion and metastasis through TGFβ2/NF-κB/Kindlin-2 axis

Objective: Recent studies have shown that tumor-associated macrophages(TAMs) play an important role in cancer invasion and metastasis. Our previous studies have reported that TAMs promote the invasion and metastasis of gastric cancer(GC) cells through the Kindlin-2 pathway. However, the mechanism needs to be clarified.Methods: THP-1 monocytes were induced by PMA/interleukin(IL)-4/IL-13 to establish an efficient TAM model in vitro and M2 macrophages were isolated via flow cytometry. A dual lucife...     

Interferon-α sensitizes human gastric cancer cells to TRAIL-induced apoptosis via activation of the c-CBL-dependent MAPK/ERK pathway

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a member of the tumor necrosis factor family that induces apoptosis in cancer cells. However, gastric cancer cells are insensitive to TRAIL. In the present study, we show that pretreatment with IFN-α enhanced TRAIL-induced apoptosis of gastric cancer MGC803 cells. IFN-α up-regulated death receptor 5 (DR5) expression and down-regulated survivin expression. Furthermore, extracellular-regulated protein kinase (ERK1/2) activation was induced by IFN-α, and a combination of IFN-α and TRAIL led to further activation of ERK1/2. Inhibition of the MAPK/ERK signaling pathway partially reversed apoptosis, as well as the expression patterns of DR5 and survivin. Moreover, the expression of the c-casitas B-lineage lymphoma (c-Cbl) family was down-regulated by IFN-α. Transfection of c-Cbl suppressed IFN-α-induced ERK activation. These results indicate that IFN-α enhances TRAIL-induced apoptosis in gastric cancer cells at least partially via downregulation of c-Cbl, and subsequent up-regulation of the MAPK/ERK pathway.     

TF/FVIIa/PAR2 promotes cell proliferation and migration via PKCα and ERK-dependent c-Jun/AP-1 pathway in colon cancer cell line SW620

Our previous study has demonstrated that tissue factor–factor VIIa (TF/FVIIa) complex promotes the proliferation and migration of colon cancer cell line SW620 through the activation of protease-activated receptor 2 (PAR2). In the current study, the underlying molecular mechanisms of TF/FVIIa/PAR2 signaling in SW620 cells were further explored, with the focus on the role of activator protein-1 (AP-1) subunit c-Jun. The results revealed that PAR2-AP and FVIIa could upregulate c-Jun expression and c-Jun phosphorylation in SW620 cells in a time-dependent manner. The effect of FVIIa was significantly blocked by anti-TF and anti-PAR2 antibodies. Protein kinase Cα (PKCα) inhibitor safingol and extracellular signal-regulated kinase 1 and 2 (ERK1/2) inhibitor U0126 abrogated the activation of c-Jun. In contrast, Ca²⁺ chelators EGTA and thapsigargin, and p38MAPK inhibitor SB203580 had no effect. Suppression of c-Jun/AP-1 activation using a natural inhibitor curcumin decreased the expression of caspase-3, MMP-9, and TF, as well as the proliferation and migration of SW620 cells induced by PAR2-AP or FVIIa. Collectively, our findings suggest that c-Jun/AP-1 activation is required for TF/FVIIa/PAR2-induced SW620 cell proliferation and migration. PKCα and ERK1/2 are located upstream of c-Jun/AP-1 in this signaling pathway. Pharmacological inhibition of this pathway might be a novel strategy for colon cancer therapy.     

α-TEA induces apoptosis of human breast cancer cells via activation of TRAIL/DR5 death receptor pathway

Vitamin E derivative RRR‐α‐tocopherol ether‐linked acetic acid analog (α‐TEA) induces apoptosis in MCF‐7 and HCC‐1954 human breast cancer cells in a dose‐ and time‐dependent manner. α‐TEA induces increased levels of tumor necrosis factor‐related apoptosis‐inducing ligand (TRAIL) and death receptor‐5 (DR5) and decreased levels of antiapoptotic factor, cellular FLICE‐like inhibitory protein (c‐FLIP L). DR5/TRAIL induced apoptosis involves downregulation of c‐FLIP (L), caspase‐8 activation, activated proapoptotic mediators tBid and Bax, mitochondrial permeability transition, and activation of caspase‐9. siRNA knockdown of either DR5 or TRAIL blocks the ability of α‐TEA to enhance DR5 protein levels, downregulate c‐FLIP(L) protein levels and induce apoptosis. Combination of α‐TEA + TRAIL acts cooperatively to induce apoptosis, and increase DR5 and decrease c‐FLIP (L) protein levels. siRNA knockdown of c‐FLIP produces a low level of spontaneous apoptosis and enhances α‐TEA‐ and TRAIL‐induced apoptosis. Taken together, these studies show that α‐TEA induces TRAIL/DR5 mitochondria‐dependent apoptosis in human breast cancer cells, and that TRAIL/DR5‐dependent increases in DR5 and decreases in c‐FLIP expression are triggered by TRAIL or α‐TEA treatments. © 2010 Wiley‐Liss, Inc.