Growth suppression of human oral cancer cells by candidate agents for cetuximab-side effects.

Cetuximab, an inhibitor of the epidermal growth factor receptor that is used widely to treat human cancers including oral squamous cell carcinoma (OSCC), has characteristic side effects of skin rash and hypomagnesemia. However, the mechanisms of and therapeutic agents for skin rashes and hypomagnesemia are still poorly understood. Our gene expression profiling analyses showed that cetuximab activates the p38 MAPK pathways in human skin cells (human keratinocyte cell line [HaCaT]) and inhibits c-Fos-related signals in human embryonic kidney cells (HEK293). We found that while the p38 inhibitor SB203580 inhibited the expression of p38 MAPK targets in HaCaT cells, flavagline reactivated c-Fos-related factors in HEK293 cells. It is noteworthy that, in addition to not interfering with the effect of cetuximab by both compounds, flavagline has additive effect for OSCC growth inhibition in vivo. Collectively, our results indicate that combination of cetuximab and these potential therapeutic agents for cetuximab-related toxicities could be a promising therapeutic strategy for patients with OSCC.

Azacitidine Mitigates Graft-versus-Host Disease via Differential Effects on the Proliferation of T Effectors and Natural Regulatory T Cells In Vivo.

Azacitidine (AzaC) mitigates graft-versus-host disease (GvHD) in both murine preclinical transplant models and in human clinical trials while maintaining a robust graft-versus-leukemia effect. Previous studies have failed to investigate the role of natural regulatory T cells (nTregs) on the mitigation of GvHD by AzaC, instead focusing on the generation of suppressive Tregs (CD4+CD25+FOXP3+) through the in vivo conversion of alloreactive donor T effectors (Teffs; CD4+CD25-FOXP3-) and the direct antiproliferative effects of AzaC on allogeneic T cells. Using B6.Foxp3DTR/GFP mice in which Tregs can be specifically ablated through administration of diphtheria toxin, we demonstrate that natural Tregs are required in the donor graft for AzaC to optimally protect against GvHD and that nTregs, unlike Teffs (CD3+FOXP3-), are resistant to the antiproliferative effects of AzaC. Gene expression analysis identified the potent cell cycle inhibitor, p21, was significantly upregulated in Teffs but not nTregs after treatment with AzaC. Furthermore, we demonstrate that Teffs deficient in p21 are less sensitive to the antiproliferative effects of AzaC. These results demonstrate that nTregs are essential for AzaC to fully protect against GvHD and have important clinical implications for future clinical trials testing AzaC as a novel method of GvHD prophylaxis in man.

The Antiproliferative and Apoptotic Effects of Capsaicin on an Oral Squamous Cancer Cell Line of Asian Origin, ORL-48.

Background and Objectives: The antitumor activities of capsaicin on various types of cancer cell lines have been reported but the effect of capsaicin on oral cancer, which is prevalent among Asians, are very limited. Thus, this study aimed to investigate the effects of capsaicin on ORL-48, an oral cancer cell line of Asian origin. Materials and Methods: Morphological changes of the ORL-48 cells treated with capsaicin were analyzed using fluorescence microscopy. The apoptotic-inducing activity of capsaicin was further confirmed by Annexin V-Fluorescein isothiocyanate / Propidium iodide (V-FITC/PI) staining using flow cytometry. In order to establish the pathway of apoptosis triggered by the compound on ORL-48 cells, caspase activity was determined and the mitochondrial pathway was verified by mitochondrial membrane potential (MMP) assay. Cell cycle analysis was also performed to identify the cell cycle phase of ORL-48 cells being inhibited by the capsaicin compound. Results: Fluorescence microscopy exhibited the presence of apoptotic features in capsaicin-treated ORL-48 cells. Apoptosis of capsaicin-treated ORL-48 cells revealed disruption of the mitochondrial-membrane potential, activation of caspase-3, -7 and -9 through an intrinsic apoptotic pathway and subsequently, apoptotic DNA fragmentation. The cell cycle arrest occurred in the G1-phase, confirming antiproliferative effect of capsaicin in a time-dependent manner. Conclusion: This study demonstrated that capsaicin is cytotoxic against ORL-48 cells and induces apoptosis in ORL-48 cells possibly through mitochondria mediated intrinsic pathway resulting in cell cycle arrest.

Local checkpoint inhibition of CTLA-4 as a monotherapy or in combination with anti-PD1 prevents the growth of murine bladder cancer.

Checkpoint blockade of CTLA-4 results in long-lasting survival benefits in metastatic cancer patients. However, patients treated with CTLA-4 blockade have suffered from immune-related adverse events, most likely due to the breadth of the induced T-cell activation. Here, we investigated the efficacy of a local low-dose anti-CTLA-4 administration for treatment of subcutaneous or orthotopic murine bladder 49 (MB49) bladder carcinoma in C57BL/6 mice. When MB49 tumors were grown s.c., peritumoral (p.t.) injection of anti-CTLA-4 treatment was equally effective as intravenous or s.c. (nontumor bearing flank) administration. Notably, p.t. injection was associated with lower circulating antibody levels and decreased IL-6 serum levels as compared to systemic treatment. Ultrasound-guided intratumoral anti-CTLA-4 antibody treatment of orthotopically growing MB49 tumors resulted in tumor regression, with more than tenfold reduction in systemic antibody levels as compared to i.v. or s.c. administration, in line with the compartmentally restrained nature of the bladder. Local anti-CTLA-4 therapy in combination with anti-PD-1 therapy resulted in complete responses, superior to each therapy alone. In addition, p.t. anti-CTLA-4 therapy was potentiated by depletion of regulatory T cells. Our results demonstrate that local anti-CTLA-4 antibody therapy is equally effective as systemic administration, but reduces systemic antibody levels and cytokine release, and enhances the response to anti-PD1 therapy.

N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP) attenuates silicotic fibrosis by suppressing apoptosis of alveolar type II epithelial cells via mediation of endoplasmic reticulum stress.

Damage to alveolar epithelial cells (AECs) caused by long-term inhalation of large amounts of silica dust plays a significant role in the pathology of silicosis. The present study was undertaken to investigate the regulatory mechanism(s) involved in type II AEC damage from silicon dioxide (SiO2) as well as the mechanism(s) related to the prevention of silicosis by the antifibrotic tetra peptide, N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP). The 2-DE results showed that SiO2 induced endoplasmic reticulum (ER) stress in A549 cells. In addition, typical apoptotic characteristics were observed using a transmission electron microscope (TEM) in A549 cells stimulated by SiO2 and in type II AECs from silicotic rats. Mechanistic study showed that both Ac-SDKP and 4-phenylbutyrate (4-PBA), an inhibiter of ER stress, attenuated GRP78, phosphor-PERK, phosphor-eIF2α, CHOP and Caspase-12 protein expression in A549 cells stimulated by SiO2 and in type II AECs from silicotic rats. Treatment with Ac-SDKP and 4-PBA in vivo effectively inhibited collagen deposition in the lungs of silicotic rats. In summary, ER stress is involved in the apoptosis of type II AECs both in vitro and in vivo. Ac-SDKP effectively suppresses SiO2-induced apoptosis in type II AECs by attenuating the Caspase-12 and PERK/eIF2α/CHOP pathway activation caused by ER stress, thus preventing silicotic fibrosis.

Growth attenuation therapy for children with severe physical and cognitive disability: Practice and perspectives of New Zealand paediatricians.

AIM: There are currently no clinical guidelines concerning the administration of growth attenuation therapy (GAT) for children (regardless of gender) with both severe physical and cognitive disability in New Zealand (NZ). This survey aimed to explore the attitudes of paediatricians towards GAT and the frequency of requests and initiation of GAT in NZ. METHODS: An online survey of paediatricians in NZ was undertaken. Questions covered both clinical experience with GAT and attitudes towards it. RESULTS: Overall, the response rate was 55% (173/317) with 162 complete responses; 25% of respondents (41/166) reported enquiries about GAT. Five had personally prescribed GAT; in total, six NZ children have undergone GAT. A total of 77% of respondents either believed GAT is appropriate or were neutral on the subject. The majority of responders (59%) believed ethical approval should be obtained as part of preparation for GAT. CONCLUSIONS: This is the first study to investigate attitudes and practices of NZ paediatricians regarding GAT for severely disabled children. Results indicate a range of views but suggest that family requests for GAT do occur and that the majority of paediatricians are not opposed to GAT in the appropriate ethical and clinical context. The development of practice guidelines for GAT may lead to a more informed decision-making process about GAT for families and paediatricians.

Daidzein Augments Cholesterol Homeostasis via ApoE to Promote Functional Recovery in Chronic Stroke.

Stroke is the world's leading cause of physiological disability, but there are currently no available agents that can be delivered early after stroke to enhance recovery. Daidzein, a soy isoflavone, is a clinically approved agent that has a neuroprotective effect in vitro, and it promotes axon growth in an animal model of optic nerve crush. The current study investigates the efficacy of daidzein on neuroprotection and functional recovery in a clinically relevant mouse model of stroke recovery. In light of the fact that cholesterols are essential lipid substrates in injury-induced synaptic remodeling, we found that daidzein enhanced the cholesterol homeostasis genetic program, including Lxr and downstream transporters, Apoe, Abca1, and Abcg1 genes in vitro. Daidzein also elevated the cholesterol homeostasis genes in the poststroke brain with Apoe, the highest expressing transporter, but did not affect infarct volume or hemispheric swelling. Despite the absence of neuroprotection, daidzein improved motor/gait function in chronic stroke and elevated synaptophysin expression. However, the daidzein-enhanced functional benefits and synaptophysin expression were abolished in Apoe-knock-out mice, suggesting the importance of daidzein-induced ApoE upregulation in fostering stroke recovery. Dissociation between daidzein-induced functional benefits and the absence of neuroprotection further suggest the presence of nonoverlapping mechanisms underlying recovery processes versus acute pathology. With its known safety in humans, early and chronic use of daidzein aimed at augmenting ApoE may serve as a novel, translatable strategy to promote functional recovery in stroke patients without adverse acute effect. SIGNIFICANCE STATEMENT: There have been recurring translational failures in treatment strategies for stroke. One underlying issue is the disparity in outcome analysis between animal and clinical studies. The former mainly depends on acute infarct size, whereas long-term functional recovery is an important outcome in patients. In an attempt to identify agents that promote functional recovery, we discovered that an FDA-approved soy isoflavone, daidzein, improved stroke-induced behavioral deficits via enhancing cholesterol homeostasis in chronic stroke, and this occurs without causing adverse effects in the acute phase. With its known safety in humans, the study suggests that the early and chronic use of daidzein serves as a potential strategy to promote functional recovery in stroke patients.

Vitamin D inhibits the occurrence of experimental cerebral malaria in mice by suppressing the host inflammatory response.

In animal models of experimental cerebral malaria (ECM), neuropathology is associated with an overwhelming inflammatory response and sequestration of leukocytes and parasite-infected RBCs in the brain. In this study, we explored the effect of vitamin D (VD; cholecalciferol) treatment on host immunity and outcome of ECM in C57BL/6 mice during Plasmodium berghei ANKA (PbA) infection. We observed that oral administration of VD both before and after PbA infection completely protected mice from ECM. VD administration significantly dampened the inducible systemic inflammatory responses with reduced circulating cytokines IFN-γ and TNF and decreased expression of these cytokines by the spleen cells. Meanwhile, VD also resulted in decreased expression of the chemokines CXCL9 and CXCL10 and cytoadhesion molecules (ICAM-1, VCAM-1, and CD36) in the brain, leading to reduced accumulation of pathogenic T cells in the brain and ultimately substantial improvement of the blood-brain barriers of PbA-infected mice. In addition, VD inhibited the differentiation, activation, and maturation of splenic dendritic cells. Meanwhile, regulatory T cells and IL-10 expression levels were upregulated upon VD treatment. These data collectively demonstrated the suppressive function of VD on host inflammatory responses, which provides significant survival benefits in the murine ECM model.

Arsenic trioxide synergistically potentiates the cytotoxic effect of fludarabine in chronic lymphocytic leukemia cells by further inactivating the Akt and ERK signaling pathways.

CLL remains an incurable disease, making it crucial to continue searching for new therapies efficient in all CLL cases. We have studied the effect of combining arsenic trioxide (ATO) with fludarabine, a frontline drug in CLL. We have found a synergistic interaction between 1 µM ATO and 5 µM fludarabine that significantly enhanced the cytotoxic effect of the individual drugs. Importantly, ATO sensitized fludarabine-resistant cells to the action of this drug. The mechanism behind this effect included the downregulation of phospho-Akt, phospho-ERK, and the Mcl-1/Bim and Bcl-2/Bax ratios. The combination of ATO and fludarabine partially overcame the survival effect induced by co-culturing CLL cells with stromal cells. Therefore, low concentrations of ATO combined with fludarabine may be an efficient therapeutic strategy in CLL patients.

Caudatin Inhibits Human Glioma Cells Growth Through Triggering DNA Damage-Mediated Cell Cycle Arrest.

Caudatin, one of the species of C-21 steroidal glycosides mainly isolated from the root of Cynanchum bungei Decne, exhibits potent anticancer activities. However, the mechanism remains poorly defined. In the present study, the growth inhibitory effect and mechanism of caudatin on human glioma cells were evaluated in vitro. The results revealed that caudatin time- and dose-dependently inhibited U251 and U87 cells growth. Flow cytometry analysis indicated that caudatin-induced growth inhibition against U251 and U87 cells was mainly achieved by the induction of G0/G1 and S-phase cell cycle arrest through triggering DNA damage, as convinced by the up-regulation of p53, p21, and histone phosphorylation, as well as the down-regulation of cyclin D1. Moreover, caudatin treatment also triggered the activation of ERK and inactivation of AKT pathway. LY294002 (an AKT inhibitor) addition enhanced caudation-induced AKT inhibition, indicating that caudatin inhibited U251 cells growth in an AKT-dependent manner. Taken together, these results indicate that caudatin may act as a novel cytostatic reagent against human glioma cells through the induction of DNA damage-mediated cell cycle arrest with the involvement of modulating MAPK and AKT pathways.

Vitamin D in cancer chemoprevention.

CONTEXT: There is increasing evidence that Vitamin D (Vit D) and its metabolites, besides their well-known calcium-related functions, may also exert antiproliferative, pro-differentiating, and immune modulatory effects on tumor cells in vitro and may also delay tumor growth in vivo. OBJECTIVE: The aim of this review is to provide fresh insight into the most recent advances on the role of Vit D and its analogues as chemopreventive drugs in cancer therapy. METHODS: A systematic review of experimental and clinical studies on Vit D and cancer was undertaken by using the major electronic health database including ISI Web of Science, Medline, PubMed, Scopus and Google Scholar. RESULTS AND CONCLUSION: Experimental and clinical observations suggest that Vit D and its analogues may be effective in preventing the malignant transformation and/or the progression of various types of human tumors including breast cancer, prostate cancer, colorectal cancer, and some hematological malignances. These findings suggest the possibility of the clinical use of these molecules as novel potential chemopreventive and anticancer agents.

Growth inhibitory activity for cancer cell lines of lapachol and its natural and semi-synthetic derivatives.

A series of 17 selected natural and semisynthetic 1,4-naphthoquinones were synthesized, and their growth inhibitory activity was evaluated in vitro. The compounds were tested on six human cancer cell lines using the MTT colorimetric assay. The data revealed that of the chemicals under study only lapachol, its acetate and 3-geranyllawsone displayed the highest activity, recording mean IC50 values ranging from 15 to 22 µM.

Depletion of plasmacytoid dendritic cells inhibits tumor growth and prevents bone metastasis of breast cancer cells.

Elevated levels of plasmacytoid dendritic cells (pDC) have been reported in breast cancer patients, but the significance remains undefined. Using three immunocompetent mouse models of breast cancer bone metastasis, we identified a key role for pDC in facilitating tumor growth through immunosuppression and aggressive osteolysis. Following infiltration of macrophages upon breast cancer dissemination, there was a steady increase in pDC within the bone, which resulted in a sustained Th2 response along with elevated levels of regulatory T cells and myeloid-derived suppressor cells. Subsequently, pDC and CD4(+) T cells, producing osteolytic cytokines, increased with tumor burden, causing severe bone damage. Microcomputed tomography and histology analyses of bone showed destruction of femur and tibia. The therapeutic significance of this finding was confirmed by depletion of pDC, which resulted in decreased tumor burden and bone loss by activating tumor-specific cytolytic CD8(+) T cells and decreasing suppressor cell populations. Thus, pDC depletion may offer a novel adjuvant strategy to therapeutically influence breast cancer bone metastasis.

Stabilization of HIF-2α induces sVEGFR-1 production from tumor-associated macrophages and decreases tumor growth in a murine melanoma model.

Macrophage secretion of vascular endothelial growth factor (VEGF) in response to hypoxia contributes to tumor growth and angiogenesis. In addition to VEGF, hypoxic macrophages stimulated with GM-CSF secrete high levels of a soluble form of the VEGF receptor (sVEGFR-1), which neutralizes VEGF and inhibits its biological activity. Using mice with a monocyte/macrophage-selective deletion of hypoxia-inducible factor (HIF)-1α or HIF-2α, we recently demonstrated that the antitumor response to GM-CSF was dependent on HIF-2α-driven sVEGFR-1 production by tumor-associated macrophages, whereas HIF-1α specifically regulated VEGF production. We therefore hypothesized that chemical stabilization of HIF-2α using an inhibitor of prolyl hydroxylase domain 3 (an upstream inhibitor of HIF-2α activation) would increase sVEGFR-1 production from GM-CSF-stimulated macrophages. Treatment of macrophages with the prolyl hydroxylase domain 3 inhibitor AKB-6899 stabilized HIF-2α and increased sVEGFR-1 production from GM-CSF-treated macrophages, with no effect on HIF-1α accumulation or VEGF production. Treatment of B16F10 melanoma-bearing mice with GM-CSF and AKB-6899 significantly reduced tumor growth compared with either drug alone. Increased levels of sVEGFR-1 mRNA, but not VEGF mRNA, were detected within the tumors of GM-CSF- and AKB-6899-treated mice, correlating with decreased tumor vascularity. Finally, the antitumor and antiangiogenic effects of AKB-6899 were abrogated when mice were simultaneously treated with a sVEGFR-1 neutralizing Ab. These results demonstrate that AKB-6899 decreases tumor growth and angiogenesis in response to GM-CSF by increasing sVEGFR-1 production from tumor-associated macrophages. Specific activation of HIF-2α can therefore decrease tumor growth and angiogenesis.

In vitro Anticancer Activity of Myricanone in Human Lung Adenocarcinoma A549 Cells.

BACKGROUND: Lung cancer is the leading cause of cancer-related mortality worldwide. Despite the new chemotherapy regimens and cytotoxic combinations investigated in multiple clinical trials in recent years, no significant improvement in the prognosis of patients with lung cancer has been achieved. Recently, scientists have focused on the potential role of extracts of traditional Chinese medicinal herbs as alternative and complementary medications for cancer treatment. Myricanone, a typical large ring of cyclic diarylheptanoids, is abundant in the bark of Myrica. Our studies have found that myricanone exerts potent anticancer activity. This study aimed to investigate the underlying mechanism of the effect of myricanone on A549 cells in vitro. METHODS: A549 cells were treated with different concentrations of myricanone for the following assays. Tritiated thymidine incorporation was used to measure growth inhibition. Flow cytometry was used to detect apoptosis and cell cycle progression, and colony formation was performed to observe the effect of myricanone on the A549 proliferation rate. RESULTS: Myricanone induced significant dose-dependent growth inhibitory effects on A549 cells with an IC50 of 3.22 µg/ml. A significant decrease in colony formation was observed. This decrease induced cell apoptosis, G1 phase arrest and the emergence of the sub-G0 peak in A549 cells. CONCLUSIONS: These results suggest that myricanone exhibits anticancer activity and may be applicable in the clinical prevention and treatment of lung cancer in the future.

Elevated SGK1 predicts resistance of breast cancer cells to Akt inhibitors.

The majority of human cancers harbour mutations promoting activation of the Akt protein kinase, and Akt inhibitors are being evaluated in clinical trials. An important question concerns the understanding of the innate mechanisms that confer resistance of tumour cells to Akt inhibitors. SGK (serum- and glucocorticoid-regulated kinase) is closely related to Akt and controlled by identical upstream regulators {PI3K (phosphoinositide 3-kinase), PDK1 (phosphoinositide-dependent kinase 1) and mTORC2 [mTOR (mammalian target of rapamycin) complex 2]}. Mutations that trigger activation of Akt would also stimulate SGK. Moreover, Akt and SGK possess analogous substrate specificities and are likely to phosphorylate overlapping substrates to promote proliferation. To investigate whether cancers possessing high SGK activity could possess innate resistance to Akt-specific inhibitors (that do not target SGK), we analysed SGK levels and sensitivity of a panel of breast cancer cells towards two distinct Akt inhibitors currently in clinical trials (AZD5363 and MK-2206). This revealed a number of Akt-inhibitor-resistant lines displaying markedly elevated SGK1 that also exhibited significant phosphorylation of the SGK1 substrate NDRG1 [N-Myc (neuroblastoma-derived Myc) downstream-regulated gene 1]. In contrast, most Akt-inhibitor-sensitive cell lines displayed low/undetectable levels of SGK1. Intriguingly, despite low SGK1 levels, several Akt-inhibitor-sensitive cells showed marked NDRG1 phosphorylation that was, unlike in the resistant cells, suppressed by Akt inhibitors. SGK1 knockdown markedly reduced proliferation of Akt-inhibitor-resistant, but not -sensitive, cells. Furthermore, treatment of Akt-inhibitor-resistant cells with an mTOR inhibitor suppressed proliferation and led to inhibition of SGK1. The results of the present study suggest that monitoring SGK1 levels as well as responses of NDRG1 phosphorylation to Akt inhibitor administration could have a use in predicting the sensitivity of tumours to compounds that target Akt. Our findings highlight the therapeutic potential that SGK inhibitors or dual Akt/SGK inhibitors might have for treatment of cancers displaying elevated SGK activity.

Microtubule-stabilizing agents delay the onset of EAE through inhibition of migration.

We have shown previously that microtubule-stabilizing agents (MSA), a class of anti-proliferative compounds, can delay disease onset and reduce cumulative disease in an experimental model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE). To explore how MSA could alter EAE disease processes, we compared the effect of administering MSA before or after peak antigen-specific proliferation and found that treatment before proliferation completely inhibited antigen-specific responses in the spleen; whereas administration of an MSA such as paclitaxel or docetaxel after peak proliferation did not. Despite the presence of antigen-specific responses in mice treated at the later time point, both treatment periods resulted in similar protection against EAE, suggesting that the protective effect of MSA in EAE could not be solely attributed to anti-proliferative activity. Instead, using in vivo migration assays, it was shown that MSA inhibit immune cell infiltration into the central nervous system (CNS). Furthermore, we found that the efficacy of an MSA could be enhanced by administering low doses of two different MSA together, such as peloruside A and ixabepilone, indicating that these MSA synergize in vivo to suppress disease. Taken together, these data suggest that MSA can suppress EAE by at least two distinct mechanisms of action--prevention of proliferation and inhibition of migration into the CNS. Finally, we have shown that a combination treatment with synergizing MSA may provide enhanced protection at lower therapeutic doses.

Renal antifibrotic effect of N-acetyl-seryl-aspartyl-lysyl-proline in diabetic rats.

BACKGROUND AND AIM: Diabetic nephropathy is the main cause of end-stage renal disease. N-acetyl-seryl-aspartyl-lysyl-proline (Ac-SDKP), a physiological tetrapeptide hydrolyzed by the angiotensin-converting enzyme (ACE), has antifibrotic effects in the cardiovascular system and in the kidney in experimental models of hypertension, heart failure and renal disease. The aim of the study was to evaluate the effect of Ac-SDKP in diabetic nephropathy and the potential additive effect of Ac-SDKP, when compared to ACE inhibitors alone, on the development of renal fibrosis. METHOD: Diabetes was induced in 28 Sprague-Dawley rats by a single intraperitoneal injection of streptozotocin. Control rats (n = 10) received only buffer solution. An ACE inhibitor (ramipril, 3 mg/kg/day) was administered to 11 diabetic rats. After 2 months, Ac-SDKP (1 mg/kg/day) was administered by osmotic minipumps for 8 weeks to 7 diabetic rats and to 6 diabetic rats treated with ramipril. Osmotic minipumps delivered saline solution in the corresponding sham-treated rats (diabetic rats, n = 10, and ramipril-treated diabetic rats, n = 5). RESULTS: Diabetic rats showed a significant increase in blood glucose level, urinary albumin excretion and renal fibrosis, and a reduction of glomerular nephrin expression with respect to control rats. Ac-SDKP administration significantly reduced renal fibrosis in diabetic rats, without significantly reducing urinary albumin excretion. Ramipril treatment caused a significant decrease in albuminuria and renal fibrosis and restored glomerular nephrin expression. Administration of Ac-SDKP, in addition to ramipril, further reduced renal fibrosis with respect to ramipril alone, while it did not improve the antiproteinuric effect of ramipril. CONCLUSION: Ac-SDKP administration reduces renal fibrosis in diabetic nephropathy. Addition of Ac-SDKP to ACE inhibition therapy improves the reduction of renal fibrosis with respect to ACE inhibition alone, suggesting a beneficial effect of this pharmacological association in diabetic nephropathy.

Apolipoprotein A-II suppressed concanavalin A-induced hepatitis via the inhibition of CD4 T cell function.

Con A-induced hepatitis has been used as a model of human autoimmune or viral hepatitis. During the process of identifying immunologically bioactive proteins in human plasma, we found that apolipoprotein A-II (ApoA-II), the second major apolipoprotein of high-density lipoprotein, inhibited the production of IFN-γ by Con A-stimulated mouse and human CD4 T cells. Con A-induced hepatitis was attenuated by the administration of ApoA-II. The beneficial effect of ApoA-II was associated with reduced leukocyte infiltration and decreased production of T cell-related cytokines and chemokines in the liver. ApoA-II inhibited the Con A-induced activation of ERK-MAPK and nuclear translocation of NFAT in CD4 T cells. Interestingly, exacerbated hepatitis was observed in ApoA-II-deficient mice, indicating that ApoA-II plays a suppressive role in Con A-induced hepatitis under physiological conditions. Moreover, the administration of ApoA-II after the onset of Con A-induced hepatitis was sufficient to suppress disease. Thus, the therapeutic effect of ApoA-II could be useful for patients with CD4 T cell-related autoimmune and viral hepatitis.

Stimulated γδ T cells increase the in vivo efficacy of trastuzumab in HER-2+ breast cancer.

One fourth of women with HER-2(+) metastatic breast carcinoma are treated with a combination regimen with trastuzumab, but the frequent resistance to this Ab requires definition of new means to improve its bioactivity. The mechanisms of action of trastuzumab involve several pathways including Ab-dependent cellular cytotoxicity. Because human γδ T lymphocytes mediate Ab-dependent cellular cytotoxicity and can be activated further by phosphoantigens, these cells are prone to improve the efficacy of Abs, as recently demonstrated for CD20(+) B cell lymphomas. Whether this concept applies as well with carcinomas remained to be demonstrated in vivo, however. In this study, we asked whether a combination of trastuzumab and phosphoantigen-stimulated γδ lymphocytes increases the efficacy of trastuzumab against HER-2(+) breast carcinoma cell lines in vivo. We report that repeated infusions of this combination had a better efficacy than that of trastuzumab alone against HER-2(+) mammary carcinoma xenografts in mice. In these models, reduction of tumor growth was observed together with trastuzumab opsonization of HER-2(+) cells and tumor infiltration by γδ lymphocytes. In addition in humans, the mammary carcinomas of 27 of 30 patients showed significant γδ T cell infiltrates. Altogether, these findings indicate that combination of trastuzumab and stimulated γδ cells represents a new strategy to improve the efficacy of Herceptin (trastuzumab) in HER-2(+) breast cancer.