Hisanori Uehara

Blockade of NF-κB activity in human prostate cancer cells is associated with suppression of angiogenesis, invasion, and metastasis

Since the NF-κB/relA transcription factor is constitutively activated in human prostate cancer cells, we determined whether blocking NF-κB/relA activity in human prostate cancer cells affected their angiogenesis, growth, and metastasis in an orthotopic nude mouse model. Highly metastatic PC-3M human prostate cancer cells were transfected with a mutated IκBα (IκBαM), which blocks NF-κB activity. Parental (PC-3M), control vector-transfected (PC-3M-Neo), and IκBαM-transfected (PC-3M–IκBαM) cells were injected into the prostate gland of nude mice. PC-3M and PC-3M-Neo cells produced rapidly growing tumors and regional lymph node metastasis, whereas PC-3M–IκBαM cells produced slow growing tumors with low metastatic potential. NF-κB signaling blockade significantly inhibited in vitro and in vivo expression of three major proangiogenic molecules, VEGF, IL-8, and MMP-9, and hence decreased neoplastic angiogenesis. Inhibition of NF-κB activity in PC-3M cells also resulted in the downregulation of MMP-9 mRNA and collagenase activity, resulting in decreased invasion through Matrigel. Collectively, these data suggest that blockade of NF-κB activity in PC-3M cells inhibits angiogenesis, invasion, and metastasis.

A mutation in the immunoproteasome subunit PSMB8 causes autoinflammation and lipodystrophy in humans

Proteasomes are multisubunit proteases that play a critical role in maintaining cellular function through the selective degradation of ubiquitinated proteins. When 3 additional β subunits, expression of which is induced by IFN-γ, are substituted for their constitutively expressed counterparts, the structure is converted to an immunoproteasome. However, the underlying roles of immunoproteasomes in human diseases are poorly understood. Using exome analysis, we found a homozygous missense mutation (G197V) in immunoproteasome subunit, β type 8 (PSMB8), which encodes one of the β subunits induced by IFN-γ in patients from 2 consanguineous families. Patients bearing this mutation suffered from autoinflammatory responses that included recurrent fever and nodular erythema together with lipodystrophy. This mutation increased assembly intermediates of immunoproteasomes, resulting in decreased proteasome function and ubiquitin-coupled protein accumulation in the patients tissues. In the patients skin and B cells, IL-6 was highly expressed, and there was reduced expression of PSMB8. Downregulation of PSMB8 inhibited the differentiation of murine and human adipocytes in vitro, and injection of siRNA against Psmb8 in mouse skin reduced adipocyte tissue volume. These findings identify PSMB8 as an essential component and regulator not only of inflammation, but also of adipocyte differentiation, and indicate that immunoproteasomes have pleiotropic functions in maintaining the homeostasis of a variety of cell types.

Simultaneous blockade of platelet-derived growth factor-receptor and epidermal growth factor-receptor signaling and systemic administration of paclitaxel as therapy for human prostate cancer metastasis in bone of nude mice.

Once prostate cancer metastasizes to bone, conventional chemotherapy is largely ineffective. We hypothesized that inhibition of phosphorylation of the epidermal growth factor receptor (EGF-R) and platelet-derived growth factor receptor (PDGF-R) expressed on tumor cells and tumor-associated endothelial cells, which is associated with tumor progression, in combination with paclitaxel would inhibit experimental prostate cancer bone metastasis and preserve bone structure. We tested this hypothesis in nude mice, using human PC-3MM2 prostate cancer cells. PC-3MM2 cells growing adjacent to bone tissue and endothelial cells within these lesions expressed phosphorylated EGF-R and PDGF-Rα and -β on their surfaces. The percentage of positive endothelial cells and the intensity of receptor expression directly correlated with proximity to bone tissue. Oral administration of PKI166 inhibited the phosphorylation of EGF-R but not PDGF-R, whereas oral administration of STI571 inhibited the phosphorylation of PDGF-R but not EGF-R. Combination therapy using oral PKI166 and STI571 with i.p. injections of paclitaxel induced a high level of apoptosis in tumor vascular endothelial cells and tumor cells in parallel with inhibition of tumor growth in the bone, preservation of bone structure, and reduction of lymph node metastasis. Collectively, these data demonstrate that blockade of phosphorylation of EGF-R and PDGF-R coupled with administration of paclitaxel significantly suppresses experimental human prostate cancer bone metastasis.

Modulation of bone microenvironment with Zoledronate enhances the therapeutic effects of STI571 and Paclitaxel against experimental bone metastasis of human prostate cancer

Prostate cancer cells metastasize to the bone where their interaction with osteoclasts and osteoblasts can lead to alterations in the structure of the bone. We determined whether the systemic administration of the bisphosphonate, zoledronate, could prevent bone lysis and halt the proliferation of human prostate cancer cells injected into the tibia of nude mice. Zoledronate did not affect the in vitro proliferation of human prostate cancer PC-3MM2 cells. The in vivo administration of zoledronate produced significant bone preservation but did not inhibit the progressive growth of PC-3MM2 cells. The systemic administration of STI571 (imatinib mesylate, Gleevec), an inhibitor of phosphorylation of the platelet-derived growth factor receptor, in combination with paclitaxel, produced apoptosis of tumor cells and bone- and tumor-associated endothelial cells. The systemic administration of zoledronate with STI571 and paclitaxel produced a significant preservation of bone structure, a decrease in tumor incidence and weight, and a decrease in incidence of lymph node metastasis. This therapeutic activity was correlated with inhibition of osteoclast function, inhibition of tumor cell proliferation, and induction of apoptosis in tumor-associated endothelial cells and tumor cells. Cancer is a heterogeneous disease that requires multimodality therapy. The present data recommend the combination of a bisphosphonate agent with protein tyrosine kinase inhibitor and an anticycling drug for the treatment of prostate cancer bone metastasis.

Phosphorylation, but not overexpression, of epidermal growth factor receptor is associated with poor prognosis of non-small cell lung cancer patients.

Epidermal growth factor receptor (EGFR) is commonly overexpressed in non-small cell lung cancer (NSCLC) and its tyrosine kinase phosphorylation is thought to be an ideal target in the treatment of patients with NSCLC. In the present study, we examined surgically obtained specimens from a series of 36 NSCLC patients for expression of EGFR, phosphorylated EGFR (p-EGFR), and HER2 by immunohistochemistry, and also examined the correlation with clinical characteristics. The positive rate of EGFR, p-EGFR, and HER2 was 97.2%, 44.4%, and 88.6%, respectively, and the overexpression rate was 80.6%, 0.0%, and 27.8%, respectively. EGFR overexpression and phosphorylation were seen at almost the same rate in each histological type of squamous and nonsquamous cell carcinoma (squamous vs. nonsquamous; 78.6% vs. 81.8% for EGFR, 35.7% vs. 50.0% for p-EGFR), while HER2 overexpression was seen less frequently in squamous cell carcinoma than in nonsquamous cell carcinoma (0.0% vs. 45.5%, P = 0.003). Univariate analysis revealed that EGFR overexpression was related to good performance status (P = 0.038) but not related to EGFR phosphorylation. EGFR phosphorylation was correlated to short time to progression (TTP) (P = 0.002) and poor prognosis (P = 0.002), although EGFR overexpression, HER2 overexpression, or EGFR-HER2 coexpression were not correlated to TTP or survival. Bivariate analysis showed EGFR phosphorylation was related to short TTP and poor prognosis both in early and advanced stages. Multivariate analyses confirmed that clinical stage, performance status, and p-EGFR expression were independently associated with increasing risk of short TTP and poor prognosis. These results suggest that phosphorylation, but not overexpression, of EGFR may be an important predictor for clinical outcome of NSCLCs.

Multifunctional interleukin‐1β promotes metastasis of human lung cancer cells in SCID mice via enhanced expression of adhesion‐, invasion‐ and angiogenesis‐related molecules

We examined whether interleukin‐1 (IL‐1), a multifunctional proinflammatory cytokine, progresses or regresses metastasis of lung cancer. Exogenous IL‐lβ enhanced expression of various cytokines (IL‐6, IL‐8, and vascular endothelial growth factor (VEGF)) and intracellular adhesion molecule‐1 (ICAM‐1) by A549, PC14, RERF‐LC‐AI, and SBC‐3 cells expressing IL‐1 receptors. A549 cells transduced with human IL‐1β‐gene with the growth‐hormone signaling‐peptide sequence (A549/IL‐1β) secreted a large amount of IL‐1β protein. Overexpression of IL‐1β resulted in augmentation of expression of the cytokines, ICAM‐1, and matrix metallo‐proteinase‐2 (MMP‐2). A549/IL‐1β cells intravenously inoculated into severe combined immunodeficiency (SCID) mice distributed to the lung more efficiently and developed lung metastasis much more rapidly than did control A549 cells. Treatment of SCID mice with anti‐IL‐1β antibody inhibited formation of lung metastasis by A549/IL‐1β cells. Moreover, A549/IL‐1β cells inoculated in the subcutis grew more rapidly, without necrosis, than did control A549 cells, which produced smaller tumors with central necrosis, suggesting involvement of angiogenesis in addition to enhanced binding in the high metastatic potential of A549/IL‐1β cells. Histological analyses showed that more host‐cell infiltration, fewer apoptotic cells, more vascularization, and higher MMP activity were observed in tumors derived from A549/IL‐1β cells, compared with tumors derived from control A549 cells. These findings suggest that IL‐1β facilitates metastasis of lung cancer via promoting multiple events, including adhesion, invasion and angiogenesis. (Cancer Sci 2003; 94: 244–252)

The therapeutic efficacy of anti vascular endothelial growth factor antibody, bevacizumab, and pemetrexed against orthotopically implanted human pleural mesothelioma cells in severe combined immunodeficient mice

Purpose: Malignant pleural mesothelioma (MPM) is an aggressive malignancy, which has a poor prognosis with a median survival of less than 1 year. The vascular endothelial growth factor (VEGF) has been reported to be an ideal therapeutic target, and a multitargeted antifolate, pemetrexed, has been clinically used for the treatment of MPM. Experimental Design: We examined the therapeutic efficacy of the antihuman VEGF neutralizing antibody, bevacizumab, in combination with pemetrexed against two different human MPM cells, EHMES-10 and MSTO-211H, orthotopically inoculated into severe combined immunodeficient mice. Results: Bevacizumab inhibited a VEGF-induced proliferation of the human endothelial cells in a dose-dependent manner, but it had no effect on the proliferation of the two MPM cell lines in vitro. The orthotopically inoculated EHMES-10 cells (VEGF high expressing) produced thoracic tumors and a large volume of bloody pleural effusion, whereas the MSTO-211H cells (VEGF low expressing) produced thoracic tumors and a small volume of bloody effusions. Treatment with bevacizumab effectively inhibited the production of thoracic tumors and dramatically prevented the production of pleural effusion by the EHMES-10 cells but not the MSTO-211H cells. Treatment with bevacizumab reduced the number of enlarged tumor-associated vessels and proliferating tumor cells. Moreover, treatment with bevacizumab in combination with pemetrexed more effectively suppressed the formation of the pleural effusion and prolonged the survival compared with the control and monotherapy in the EHMES-10 cell–bearing severe combined immunodeficient mice. Conclusions: These results suggest that the combined use of bevacizumab and pemetrexed may therefore be promising for controlling the progression of MPM highly expressing VEGF.

Lymphotoxin Signal Promotes Thymic Organogenesis by Eliciting RANK Expression in the Embryonic Thymic Stroma

It has recently become clear that signals mediated by members of the TNFR superfamily, including lymphotoxin-β receptor (LTβR), receptor activator for NF-κB (RANK), and CD40, play essential roles in organizing the integrity of medullary thymic epithelial cells (mTECs) required for the establishment of self-tolerance. However, details of the mechanism responsible for the unique and cooperative action of individual and multiple TNFR superfamily members during mTEC differentiation still remain enigmatic. In this study, we show that the LTβR signal upregulates expression of RANK in the thymic stroma, thereby promoting accessibility to the RANK ligand necessary for mTEC differentiation. Cooperation between the LTβR and RANK signals for optimal mTEC differentiation was underscored by the exaggerated defect of thymic organogenesis observed in mice doubly deficient for these signals. In contrast, we observed little cooperation between the LTβR and CD40 signals. Thus, the LTβR signal exhibits a novel and unique function in promoting RANK activity for mTEC organization, indicating a link between thymic organogenesis mediated by multiple cytokine signals and the control of autoimmunity.

Sonic hedgehog relates to colorectal carcinogenesis

AimThe activation of Hedgehog signaling, which is critical to normal mammalian gastrointestinal development, is implicated in the development of various tumors, including colorectal cancer. In the pancreas, a precursor lesion overexpresses the Sonic hedgehog (Shh) when compared with normal tissue and cancer. The present study was designed to investigate Shh related protein expression in hyperplastic polyps and the adenoma-carcinoma sequence in the colon and rectum.MethodsSeventeen hyperplastic polyps, 24 adenomas of the colon, 69 adenocarcinomas (31 well-differentiated, 38 moderately-differentiated), and 30 normal colon samples were used in the study. We checked the expression of Shh, both patched (Ptch) and smoothened (Smo), by immunohistochemistry and compared the expression rate of each group.ResultsAlmost all adenomas, 22 of 23 (96%), expressed Shh. In other groups, 4 of 17 hyperplastic polyps (24%), 7 of 31 well-differentiated adenocarcinomas (23%), 13 of 38 moderately-differentiated adenocarcinomas (34%) and none of the 30 normal samples expressed Shh. The rate of expression in Ptch and Smo gradually increased in accordance with tumor progression.ConclusionThis result indicates that Shh-related carcinogenesis and Shh expression may be a trigger for the adenoma-carcinoma sequence. This study suggests a potential therapeutic target of hedgehog blockade in carcinogenesis.

E7080, a Multi–Tyrosine Kinase Inhibitor, Suppresses the Progression of Malignant Pleural Mesothelioma with Different Proangiogenic Cytokine Production Profiles

Purpose: Malignant pleural mesothelioma (MPM) is a biologically heterogeneous malignant disease with a poor prognosis. We reported previously that the anti–vascular endothelial growth factor (VEGF) antibody, bevacizumab, effectively inhibited the progression of VEGF-high-producing (but not VEGF-low-producing) MPM cells in orthotopic implantation models, indicating the need for novel therapeutic strategies to improve the poor prognosis of this disease. Therefore, we focused on the multi–tyrosine kinase inhibitor E7080 and assessed its therapeutic efficacy against MPM cells with different proangiogenic cytokine production profiles. Experimental Design: The efficacy of E7080 was assayed in orthotopic implantation of severe combined immunodeficient mouse models with three human MPM cell lines (MSTO-211H, NCI-H290, and Y-MESO-14). Results: With regard to proangiogenic cytokine production profiles, MSTO-211H and Y-MESO-14 cells were MPM cells producing high levels of fibroblast growth factor-2 and VEGF, respectively. NCI-H290 cells produced low levels of fibroblast growth factor-2 and VEGF compared with the other two cell lines. E7080 potently suppressed the phosphorylation of VEGF receptor-2 and FGF receptor 1 and, thus, inhibited proliferation of endothelial cells, but not that of the MPM cell lines, in vitro. Orthotopically inoculated MSTO-211H cells produced only thoracic tumors, whereas NCI-H290 and Y-MESO-14 cells also developed pleural effusions. Treatment with E7080 potently inhibited the progression of these three MPM cell lines and markedly prolonged mouse survival, which was associated with decreased numbers of tumor-associated vessels and proliferating MPM cells in the tumor. Conclusions: These results strongly suggest broad-spectrum activity of E7080 against MPM with different proangiogenic cytokine production profiles in humans. (Clin Cancer Res 2009;15(23):7229–37)