Relationship between vascular endothelial growth factor and nuclear factor-kappaB in renal cell tumors

A five-gene methylation signature predicts overall survival of patients with clear cell renal cell carcinoma

BACKGROUND

In this study, we aimed to screen methylation signatures associated with the prognosis of patients with clear cell renal cell carcinoma (ccRCC).

METHODS

Gene expression and methylation profiles of ccRCC patients were downloaded from publicly available databases, and differentially expressed genes (DEGs)-differentially methylated genes (DMGs) were obtained. Subsequently, gene set enrichment and transcription factor (TF) regulatory network analyses were performed. In addition, a prognostic model was constructed and the relationship between disease progression and immunity was analyzed.

RESULTS

A total of 23 common DEGs-DMGs were analyzed, among which 14 DEGs-DMGs were obtained with a cutoff value of PCC < 0 and p < 0.05. The enrichment analysis showed that the 14 DEGs-DMGs were enriched in three GO terms and three KEGG pathways. In addition, a total of six TFs were shown to be associated with the 14 DEGs-DMGs, including RP58, SOX9, NF-κB65, ATF6, OCT, and IK2. A prognostic model using five optimized DEGs-DMGs which efficiently predicted survival was constructed and validated using the GSE105288 dataset. Additionally, four types of immune cells (NK cells, macrophages, neutrophils, and cancer-associated fibroblasts), as well as ESTIMATE, immune, and stromal scores were found to be significantly correlated with ccRCC progression (normal, primary, and metastasis) in addition to the five optimized DEGs-DMGs.

CONCLUSION

A five-gene methylation signature with the predictive ability for ccRCC prognosis was investigated in this study, consisting of CCNB2, CDKN1C, CTSH, E2F2, and ERMP1. In addition, potential targets for methylation-mediated immunotherapy were highlighted.

Differential behavior of NF-κB, IκBα and EGFR during the renal carcinogenic process in an experimental model in vivo

Renal cell carcinoma (RCC) is the most common type of cancer of the adult kidney. It is generally asymptomatic even at advanced stages, so opportune diagnosis is rare, making it almost impossible to study this cancer at its early stages. RCC tumors induced by ferric nitrilotriacetate (FeNTA) in rats histologically correspond to the human clear cell RCC subtype (ccRCC) and the exposure to this carcinogen during either one or two months leads to different early stages of neoplastic development. High levels of nuclear factor kappa B (NF-κB) and epidermal growth factor receptor (EGFR) as well as low levels of NF-κB inhibitor alpha (IκBα) are frequent in human RCC, but their status in FeNTA-induced tumors and their evolution along renal carcinogenesis is unclear. On this basis, in the present study NF-κB, IκBα and EGFR behavior was analyzed at different stages of the experimental renal carcinogenesis model. Similar to patients with RCC, neoplastic tissue showed high levels of p65, one of the predominant subunits of NF-κB in ccRCC and of EGFR (protein and mRNA), as well as a decrease in the levels of NF-κB's main inhibitor, IκBα, resulting in a classic oncogenic combination. Conversely, different responses were observed at early stages of carcinogenesis. After one month of FeNTA-exposure, NF-κB activity and EGFR levels augmented; but unexpectedly, IκBα also did. While after two months, NF-κB activity diminished, but EGFR and IκBα levels remained elevated. In conclusion, FeNTA-induced tumors and RCC human neoplasms are analogues regarding to the classic NF-κB, IκBα and EGFR behavior, and distinctive non-conventional combination of changes is developed at each early stage studied. The results obtained suggest that the dysregulation of the analyzed molecules could be related to different signaling pathways and therefore, to particular effects depending on the phase of the carcinogenic process.

Monitoring the Early Antiproliferative Effect of the Analgesic-Antitumor Peptide, BmK AGAP on Breast Cancer Using Intravoxel Incoherent Motion With a Reduced Distribution of Four b-Values

Background: The present study aimed to investigate the possibility of using intravoxel incoherent motion (IVIM) diffusion magnetic resonance imaging (MRI) to quantitatively assess the early therapeutic effect of the analgesic–antitumor peptide BmK AGAP on breast cancer and also evaluate the medical value of a reduced distribution of four b-values.

Methods: IVIM diffusion MRI using 10 b-values and 4 b-values (0–1,000 s/mm²) was performed at five different time points on BALB/c mice bearing xenograft breast tumors treated with BmK AGAP. Variability in Dslow, Dfast, PF, and ADC derived from the set of 10 b-values and 4 b-values was assessed to evaluate the antitumor effect of BmK AGAP on breast tumor.

Results: The data showed that PF values significantly decreased in rBmK AGAP-treated mice on day 12 (P = 0.044). PF displayed the greatest AUC but with a poor medical value (AUC = 0.65). The data showed no significant difference between IVIM measurements acquired from the two sets of b-values at different time points except in the PF on the day 3. The within-subject coefficients of variation were relatively higher in Dfast and PF. However, except for a case noticed on day 0 in PF measurements, the results indicated no statistically significant difference at various time points in the rBmK AGAP-treated or the untreated group (P < 0.05).

Conclusion: IVIM showed poor medical value in the early evaluation of the antiproliferative effect of rBmK AGAP in breast cancer, suggesting sensitivity in PF. A reduced distribution of four b-values may provide remarkable measurements but with a potential loss of accuracy in the perfusion-related parameter PF.

Knockdown of NF-κB1 by shRNA Inhibits the Growth of Renal Cell Carcinoma In Vitro and In Vivo

Renal cell carcinoma (RCC) accounts for approximately 2%–3% of human malignancies and is the most aggressive among urologic tumors. Biological heterogeneity, drug resistance, and chemotherapy side effects are the biggest obstacles to the effective treatment of RCC. The NF-κB transcription factor is one of several molecules identified to be responsible for the aggressive phenotype of this tumor. In the past decade, several studies have demonstrated the activation of NF-κB in RCC, and many have implicated NF-κB1 (p50) as an important molecule in tumor progression and metastasis. In the present study, a lentivirus was used to deliver shRNA targeting NF-κB1 into mouse RCC (Renca) cells. It was determined that the knockdown of the NF-κB1 gene led to a reduction in cell proliferation and late apoptosis/necrosis in vitro. Flow cytometry analysis demonstrated G₂/M arrest in the cells. In addition, immunoblotting analysis revealed a significant increase in cyclin B1 and Bax. In vivo experiments showed that Renca-shRNA-NF-κB1 cells have significantly diminished tumorigenicity. Moreover, immunohistochemical analysis revealed an increase in necrotic areas of Renca-shRNA-NF-κB1 tumors. Thus, this study indicates that downregulation of NF-κB1 can suppress RCC tumorigenesis by inducing late apoptosis/necrosis. Therefore, NF-κB1 may be a potential therapeutic target for RCC.

Gelsolin, NF-κB, and p53 expression in clear cell renal cell carcinoma: Impact on outcome

OBJECTIVES

To examine the prognostic significance of Gelsolin, NF-κB, and p53 in clear cell renal cell carcinoma (CRCC), which has an unpredictable behavior and tendency for recurrence and metastasis.

MATERIALS AND METHODS

Immunohistochemistry was performed on 100 consecutive cases of CRCC using antibodies against Gelsolin, NF-κB, and p53. Tumors were grouped by nuclear grade (NG) as low NG (NG1, 2) or high NG (NG3, 4), and by pathological stage as localized (pT1, 2) or locally invasive (pT3, 4). Clinical stage was grouped as early stage (stage I, II) or late stage (stage III, IV). Evaluation was based on cytoplasmic (NF-κB(Cyt)) and nuclear (NF-κB(Nuc)) expression for NF-κB, nuclear expression for p53, membranous and cytoplasmic expression for Gelsolin.

RESULTS

Gelsolin expression correlated with high NG (p = 0.001), metastasis (p = 0.003), late stage (p = 0.008), and cancer death (p = 0.001). NF-κB(Cyt) expression correlated with high NG (p = 0.002), perirenal invasion (p = 0.010), local invasion (p = 0.020), and late stage (p= 0.003). NF-κB(Nuc) expression failed to predict the prognosis of CRCC. p53 expression correlated with high NG (p = 0.045), lymphovascular invasion (p = 0.05), metastasis (p = 0.001), late stage (p = 0.028), and cancer death (p = 0.034). However, only Gelsolin was found to correlate with disease-specific survival, (p = 0.006), and neither NF-κB nor p53 showed such relation.

CONCLUSION

Expressions of Gelsolin, NF-κB(Cyt), and p53 associated with aggressive behavior of CRCC, while Gelsolin expression specifically indicated poor disease-specific survival. The results of the present study served to determine biomarkers for predicting high-risk patients with CRCC, expected to show aggressive phenotype.

Involvement of the NF-кB/p50/Bcl-3 complex in response to antiangiogenic therapy in a mouse model of metastatic renal cell carcinoma

Renal cell carcinoma (RCC) represents approximately 2-3% of human malignancies. Nuclear transcription factor кB (NF-кB) is composed of a family of transcription factors that have been associated with the development and progression of RCC. Endostatin (ES) is a fragment of collagen XVIII that possesses antiangiogenic activity. In this study, we evaluated the expression of NF-кB in metastatic tumor cells from animals treated with ES. Balb/c-bearing Renca-EGFP cells were treated with NIH/3T3-LendSN or NIH/3T3-LXSN cells as a control. At the end of the in vivo experiment, plasma Renca-EGFP-sorted cells and tissue lung samples were collected. A real-time PCR array for NF-κB target genes revealed that ES therapy led to down regulation of Bcl-3 (P<0.031), NF-кB1 (P<0.001) and c-Rel (P<0.004) in the ES-treated group. Using an electrophoretic mobility shift assay (EMSA), we observed a reduction in NF-kB binding activity in ES-treated Renca-EGP cells. Furthermore, a supershift assay showed a clear shift of the NF-кB DNA band in samples incubated with a p50 antibody. By immunohistochemistry analysis, ES treatment resulted in a significant reduction in expression of p50. (ES vs. control P<0.05). The immunoprecipitation experiments confirmed the presence of a p50/Bcl-3 complex in nuclear extracts from cells of metastatic lung tissues. Our findings indicate that p50 and Bcl-3 plays a regulatory role in gene transcription in RCC.

Vascular endothelial growth factor expression in ovarian serous carcinomas and its effect on tumor proliferation

Introduction:

Vascular endothelial growth factor (VEGF), an endothelial mitogen, acts through VEGF receptors (VEGFRs) on the endothelial cells. During neoplastic transformation, it is hypothesized that the tumor expresses VEGF and also acquire VEGF receptor, enabling VEGF action in an autocrine and paracrine manner with varied effects on the tumor growth and progression. This study on ovarian serous carcinomas (OSCs) was done to determine the expression of VEGF and to correlate it with tumor proliferation.

Material and Methods:

Forty cases of OSCs were included. Immunohistochemistry was performed for VEGF and Ki-67. The VEGF slides were assigned an immunohistochemical score based on the staining intensity (a) and the percentage of tumor cells staining (b). The sum of both (a) and (b) ranged from 0-6. VEGF was considered positive when the score was more than 2. For Ki-67, maximally immunostained areas were selected; 500 cells counted and positive fraction determined. Mann Whitney test was used to determine the difference in the median value of Ki-67 between VEGF positive tumors and VEGF negative tumors.

Results:

Of the 40 cases, 32 cases had a VEGF score of >2 (positive) and 8 cases had VEGF score <2 (negative). The Ki-67 score ranged from 2-98%, with mean of 51%. The median Ki-67 index was much higher in VEGF positive cases as compared to VEGF negative tumors (57.5% vs. 40%). However, the difference in the two categories did not reach statistical significance (P = 0.45, Mann Whitney test).

Conclusion:

Ovarian serous carcinomas express VEGF in a significant number of cases (80% in the present study) although its potential mitogenic effect on tumor cells was not confirmed.

NFκB-mediated cyclin D1 expression by microRNA-21 influences renal cancer cell proliferation

MicroRNAs regulate post-transcriptomic landscape in many tumors including renal cell carcinoma. We have recently shown significantly increased expression of miR-21 in renal tumors and that this miRNA contributes to the proliferation of renal cancer cells in culture. However, the mechanism by which miR-21 regulates renal cancer cell proliferation is poorly understood. Addiction to constitutive NFκB activity is hallmark of many cancers including renal cancer. Using miR-21 Sponge in renal cancer cells to block endogenous function of miR-21, we show inhibition of phosphorylation of p65 subunit of NFκB, IKKβ and IκB, which results in attenuation of NFκB transcriptional activity. Subtle reduction in the tumor suppressor PTEN has been linked to various malignancies. We showed previously that miR-21 targeted PTEN in renal cancer cells. Inhibition of PTEN by siRNAs restored miR-21 Sponge-induced suppression of phosphorylation of p65, IKKβ, IκB and NFκB transcriptional activity along with reversal of miR-21 Sponge-reduced phosphorylation of Akt. Expression of constitutively active Akt protected against miR-21 Sponge- and PTEN-mediated decrease in p65/IKKβ/IκB phosphorylation and NFκB transcriptional activity. Furthermore, IKKβ and p65 were required for miR-21-induced renal cancer cell proliferation. Interestingly, miR-21 controlled the expression of cyclin D1 through NFκB-dependent transcription. Finally, we demonstrate that miR-21-regulated renal cancer cell proliferation is mediated by cyclin D1 and CDK4. Together, our results establish a molecular order of a phosphatase-kinase couple involving PTEN/Akt/IKKβ and NFκB-dependent cyclin D1 expression for renal carcinoma cell proliferation by increased miR-21 levels.

Ablation of SGK1 impairs endothelial cell migration and tube formation leading to decreased neo-angiogenesis following myocardial infarction

Serum and glucocorticoid inducible kinase 1 (SGK1) plays a pivotal role in early angiogenesis during embryonic development. In this study, we sought to define the SGK1 downstream signalling pathways in the adult heart and to elucidate their role in cardiac neo-angiogenesis and wound healing after myocardial ischemia. To this end, we employed a viable SGK1 knockout mouse model generated in a 129/SvJ background. Ablation of SGK1 in these mice caused a significant decrease in phosphorylation of SGK1 target protein NDRG1, which correlated with alterations in NF-κB signalling and expression of its downstream target protein, VEGF-A. Disruption of these signalling pathways was accompanied by smaller heart and body size. Moreover, the lack of SGK1 led to defective endothelial cell (ECs) migration and tube formation in vitro, and increased scarring with decreased angiogenesis in vivo after myocardial infarct. This study underscores the importance of SGK1 signalling in cardiac neo-angiogenesis and wound healing after an ischemic insult in vivo.

Different cellular localization of NF-κB p65 expression as an indicator of different prognoses of stage I-III gastric cancer patients

BACKGROUND

Nuclear factor-κB p65 (NF-κB p65) may play a significant role as a biomarker in tumor progression and metastasis. However, the correlation between cellular localization of NF-κB p65 expression and the prognosis of gastric cancer (GC) patients has not been studied. The present study was designed to investigate the location of NF-κB p65 expression in GC, and evaluate its correlation with clinicopathological parameters of GC patients.

METHODS

NF-κB p65 expressions in GC tissue and corresponding nonmalignant tissue from gastrectomy of 115 stage I-III GC patients were detected by immunohistochemistry. In addition, correlations between the staining results and the clinicopathologic features and survival of the GC patients were analyzed.

RESULTS

The percentage of NF-κB p65 expression in GC tissue and the corresponding nonmalignant tissue was 73.9% and 46.80%, respectively. No significant correlation was found between NF-κB p65 expression and the clinicopathologic parameters. Cox univariate analysis indicated that both nuclear staining and cytoplasmic staining of NF-κB p65 expression correlated with the prognosis of GC patients (log-rank, p = 0.0182; p = 0.0144, respectively).

CONCLUSION

High nuclear expression of NF-κB p65 is an independent prognostic marker predicting a better survival, while high cytoplasmic staining indicates a worse prognosis of GC patients.

Advanced glycation end-products disrupt the blood-brain barrier by stimulating the release of transforming growth factor-β by pericytes and vascular endothelial growth factor and matrix metalloproteinase-2 by endothelial cells in vitro

Diabetic encephalopathy is now accepted as an important complication of diabetes. The breakdown of the blood-brain barrier (BBB) is associated with dementia in patients with type 2 diabetes mellitus (T2DM). The purpose of this study was to identify the possible mechanisms responsible for the disruption of the BBB after exposure to advanced glycation end-products (AGEs). We investigated the effect of AGEs on the basement membrane and the barrier property of the BBB by Western blot analysis, using our newly established lines of human brain microvascular endothelial cell (BMEC), pericytes, and astrocytes. AGEs reduced the expression of claudin-5 in BMECs by increasing the autocrine signaling through vascular endothelial growth factor (VEGF) and matrix metalloproteinase-2 (MMP-2) secreted by the BMECs themselves. Furthermore, AGEs increased the amount of fibronectin in the pericytes through a similar up-regulation of the autocrine transforming growth factor (TGF)-β released by pericytes. These results indicated that AGEs induce basement membrane hypertrophy of the BBB by increasing the degree of autocrine TGF-β signaling by pericytes, and thereby disrupt the BBB through the up-regulation of VEGF and MMP-2 in BMECs under diabetic conditions.

A functional insertion/deletion polymorphism (-94 ins/del ATTG) in the promoter region of the NFKB1 gene is related to the risk of renal cell carcinoma

OBJECTIVE

Activated nuclear factor-ĸB is associated with the pathogenesis of numerous malignancies, including renal cell carcinoma (RCC). This study aimed to clarify the influence of a common insertion/deletion polymorphism (-94 ins/del ATTG, rs28362491) in the NFKB1 promoter on RCC susceptibility.

METHODS

We genotyped the NFKB1 -94 ins/del ATTG promoter polymorphism by the TaqMan method and assessed the association with RCC risk, clinicopathological parameters in a case-control study of 1,027 cases and 1,094 controls.

RESULTS

The genotype frequencies were significantly different between RCC cases and controls (p = 0.046). Compared with individuals carrying the ins/del + del/del genotypes, those with the ins/ins genotype had an increased RCC risk [p = 0.036, adjusted odds ratio (OR) = 1.23, 95% confidence interval (CI) = 1.02-1.48], particularly in the subgroup of younger age (p = 0.005, adjusted OR = 1.42, 95% CI = 1.11-1.83) and never smokers (p = 0.013, adjusted OR = 1.34, 95% CI = 1.07-1.69). Furthermore, the polymorphism was significantly associated with the risk of developing localized stage RCC (p = 0.020, OR = 1.26, 95% CI = 1.04-1.53).

CONCLUSIONS

The functional NFKB1 promoter polymorphism is associated with an increased risk of RCC.

Vascular protective potential of the total flavanol glycosides from Abacopteris penangiana via modulating nuclear transcription factor-κB signaling pathway and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

"Sanxuelian", the rhizome of Abacopteris penangiana (AP), is traditionally used in Chinese medicine for the treatment of blood circulation stasis, hemorheology barriers, edema and inflammation for patients of metabolic syndrome. This study was to investigate the protective effect of the total flavanol glycosides from AP (FAP) on diabetic vascular impairments by measuring the extents of oxidative stress and inflammatory response in mice.

MATERIALS AND METHODS

The experimental aortic pathology in diabetic mice was induced by fed on high-fat diet and injected with streptozotocin. The activities of FAP on attenuating aortas injuries, hypoglycemic, hypolipidemic, inhibiting oxidative stress and anti-inflammation were investigated. Additionally, the aortic expressions of nuclear transcription factor-κB (NFκB) were determined by western blot and immunohistochemistry analysis. Furthermore, the effects of FAP on human umbilical vein endothelia cells (HUVECs) were studied.

RESULTS

In animal study, the results showed that FAP enhanced the activities of antioxidant enzymes and attenuated the levels of proinflammatory cytokines. The plasma lipid profiles and glucose level in FAP treated groups were significantly decreased along with the vascular impairments were alleviated. Moreover, the aortic expression of NFκB was decreased. In cellular experiment, FAP could inhibit the apoptosis of HUVECs induced by H(2)O(2).

CONCLUSIONS

The results indicated that FAP had hypolipidemic, hypoglycemic and vascular protective activities and represented a potential herb for the treatment of aortic pathology involved with metabolic syndrome.

Advanced glycation end-products induce basement membrane hypertrophy in endoneurial microvessels and disrupt the blood-nerve barrier by stimulating the release of TGF-β and vascular endothelial growth factor (VEGF) by pericytes

AIMS/HYPOTHESIS

The breakdown of the blood-nerve barrier (BNB) is considered to be a key step in diabetic neuropathy. Although basement membrane hypertrophy and breakdown of the BNB are characteristic features of diabetic neuropathy, the underlying pathogenesis remains unclear. The purpose of the present study was to identify the possible mechanisms responsible for inducing the hypertrophy of basement membrane and the disruption of the BNB after exposure to AGEs.

METHODS

The newly established human peripheral nerve microvascular endothelial cell (PnMEC) and pericyte cell lines were used to elucidate which cell types constituting the BNB regulate the basement membrane and to investigate the effect of AGEs on the basement membrane of the BNB using western blot analysis.

RESULTS

Fibronectin, collagen type IV and tissue inhibitor of metalloproteinase (TIMP-1) protein were produced mainly by peripheral nerve pericytes, indicating that the basement membrane of the BNB is regulated mainly by these cells. AGEs reduced the production of claudin-5 in PnMECs by increasing autocrine signalling through vascular endothelial growth factor (VEGF) secreted by the PnMECs themselves. Furthermore, AGEs increased the amount of fibronectin, collagen type IV and TIMP-1 in pericytes through a similar upregulation of autocrine VEGF and transforming growth factor (TGF)-β released by pericytes.

CONCLUSIONS/INTERPRETATION

These results indicate that pericytes may be the main regulators of the basement membrane at the BNB. AGEs induce basement membrane hypertrophy and disrupt the BNB by increasing autocrine VEGF and TGF-β signalling by pericytes under diabetic conditions.

Osteopontin expression correlates with nuclear factor-κB activation and apoptosis downregulation in clear cell renal cell carcinoma

Osteopontin (OPN) is a phosphoglycoprotein implicated in tumorigenesis and tumor cell metastasis. Apoptosis inhibition is one of the mechanisms that contribute to development and progression of cancer, and might be initiated by OPN interaction with tumor cells. The aim of this study was to analyze the relation between OPN and nuclear factor-kappa B (NF-κB) expression in clear cell renal cell carcinoma (CCRCC), as well as their relation to apoptotic activity of tumor cells. Expression of OPN protein and p65 NF-κB subunit was analyzed immunohistochemically in 87 CCRCC samples, and compared mutually and with apoptotic index. Expression of OPN mRNA was analyzed using quantitative real-time PCR and compared with OPN and NF-κB protein expression in 22 CCRCC samples. Statistical analysis showed an association of p65 NF-κB with OPN mRNA (p=0.015) and protein (p<0.001). Also, we found an inverse relationship of OPN with NF-κB protein expression and apoptotic activity of tumor cells (p=0.006 and p=0.022, respectively). Our results indicate that p65 NF-κB signaling pathway may be involved in OPN-mediated CCRCC progression, partly by protecting tumor cells from apoptosis. Therefore, both molecules can constitute potential targets for therapeutic intervention in CCRCC.

Different expression patterns of pAkt, NF-κB and cyclin D1 proteins during the invasion process of head and neck squamous cell carcinoma: an in vitro approach

BACKGROUND

Several signaling pathways are involved in the progression of squamous cell carcinoma. Among them, activated PI3K/Akt may result in NF-κB nuclear translocation, thus leading to the transcription of genes enrolled in cellular invasion and proliferation, such as cyclin D1. This study sought to evaluate the expression of pAkt, NF-κB and cyclin D1 proteins in head and neck squamous cell carcinoma cell lines and their respective in vitro-obtained invasive clones.

METHODS

Squamous cell carcinoma cell lines originating from the tongue, pharynx and the metastatic lymph node were submitted to an in vitro invasion assay to select invasive clones. All experimental groups were submitted to immunofluorescence and Western blot assays. Statistical analysis was performed through a Student's t-test with a significance level of 5%.

RESULTS

The pAkt and NF-κB expression differed from cytoplasm and nucleus depending on the studied cell line. The invasive clone from the tongue presented a network-like structure of pAkt's cytoplasmic expression. This lineage as well as the invasive clone from pharynx also showed pAkt and NF-κB nuclear transportation. Significant pAkt and NF-κB increases were observed in the tongue and pharynx invasive clones. Cyclin D1 was detected in the nucleus of all studied cells and was significantly enhanced in the invasive clones from tongue and pharynx.

CONCLUSION

This study suggests the participation of pAkt, NF-κB and cyclin D1 in the invasion process of head and neck squamous cell carcinoma. Moreover, cytoplasmic pAkt network-like structure was probably related to cytoskeleton changes presented during invasion.

The role of TLR4 in photoreceptor {alpha}a crystallin upregulation during early experimental autoimmune uveitis

Purpose. Previous studies indicate that the upregulation of alphaA crystallin prevents photoreceptor mitochondrial oxidative stress-mediated apoptosis in experimental autoimmune uveitis (EAU). In this study, the role of TLR4 was investigated in the upregulation of alphaA crystallin in the retinas of animals with EAU. Methods. TLR4(-/-), iNOS(-/-), TNF-alpha(-/-), MyD88(-/-), wild-type (WT) control (C57BL/6), and nude mice (B6.Cg-Foxn1(nu)) were immunized with IRBP mixed with complete Freund's adjuvant; eyes were enucleated on day 7 after immunization. Real-time polymerase chain reaction was first used to detect upregulated inflammatory cytokines and alphaA crystallin in retinas with EAU; confirmed with Western blot analysis, and the site of upregulation was localized by immunohistochemistry. Oxidative stress was localized using 8-OHdG, and TUNEL staining was used to detect apoptosis. Results. In early EAU, increased expression of TNF-alpha, iNOS, and alphaA crystallin genes were detected in the retinas of WT mice, whereas such upregulation was absent in TLR4-deficient mice (P < 0.001). alphaA Crystallin was not elevated in MyD88(-/-), TNF-alpha(-/-), and iNOS(-/-) mice with EAU. Immunostaining revealed TNF-alpha, iNOS, and alphaA crystallin localization in the photoreceptor inner segments and outer plexiform layer in the WT controls with EAU; but such staining was absent in TLR4-deficient mice with EAU. 8-OHdG staining showed oxidative stress in the photoreceptors in WT mice with EAU and there was no apoptosis. Conclusions. TLR4 plays an important role in the upregulation of alphaA crystallin through the interaction of MyD88 and the subsequent generation of TNF-alpha and iNOS in the EAU retina. Such crystallin upregulation may prevent oxidative stress-mediated apoptosis of photoreceptors in uveitis.

Inhibition of nuclear factor kappa B attenuates tumour progression in an animal model of renal cell carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a highly metastatic and lethal disease with few efficacious treatments. Many studies have shown that the ubiquitous transcription factor nuclear factor kappa B (NF-kappaB) plays a key role in the development and progression of many cancers including RCC. The aim of this investigation was to evaluate the anti-cancer effect of pyrrolidine dithiocarbamate (PDTC), a NF-kappaB inhibitor, in a murine xenograft model of RCC.

METHODS

The metastatic human RCC cell line, SN12K1, was inoculated into the left kidneys of severe combined immunodeficiency mice and the effect of semi-continuous PDTC treatment (50 mg/kg) on RCC growth analysed 5 weeks later. The analyses carried out in three groups (no treatment, RCC alone and RCC + PDTC) at 5 weeks were: renal weight, protein expression by immunohistochemistry and Western immunoblot, apoptosis (TdT-mediated nick end labelling and morphology) and mitosis (morphology).

RESULTS

PDTC significantly decreased RCC growth and the expression of NF-kappaB subunits (p50, p52, c-Rel and RelB), upstream IKK-beta and IKK-gamma, but did not induce any changes in the expression of IkappaB-alpha and IkappaB-beta. RCC growth was associated with a significant decrease in the expression of the anti-apoptotic proteins Bcl-2 and Bcl-(XL) and increase in pro-apoptotic Bax, all of which were reversed by PDTC. Cell proliferation was significantly reduced by PDTC.

CONCLUSION

The results demonstrate the potential anti-cancer benefits of treating NF-kappaB positive RCCs with NF-kappaB inhibitors like PDTC.