KDF1 Promoted Proliferation, Migration and Invasion of Lung Adenocarcinoma Cells through Activating STAT3 and AKT Pathway.

KDF1 has been reported to be correlated with carcinogenesis. However, its role and mechanism are far from clear. To explore the possible role and underlying mechanism of KDF1 in lung adenocarcinoma (LUAD), we investigated KDF1 expression in LUAD tissues and the influence of KDF1 in the phenotype of LUAD cells (A549 and PC-9) as well as the underlying mechanism. Compared to non-tumor lung epithelial cells, KDF1 was upregulated in the cancer cells of the majority of LUAD patients, and its expression was correlated with tumor size. Patients with enhanced KDF1 in cancer cells (compared with paired adjacent non-neoplastic lung epithelial cells) had shorter overall survival than patients with no increased KDF1 in cancer cells. Knockdown of KDF1 inhibited the migration, proliferation and invasion of LUAD cells in vitro. And overexpression of KDF1 increased the growth of the subcutaneous tumors in mice. In terms of molecular mechanisms, overexpression of KDF1 induced the expression of AKT, p-AKT and p-STAT3. In KDF1-overexpressing A549 cells, inhibition of the STAT3 pathway decreased the level of AKT and p-AKT, whereas inhibition of the AKT pathway had no effect on the activation of STAT3. Inhibition of STAT3 or AKT pathways reversed the promoting effects of KDF1 overexpression on the LUAD cell phenotype and STAT3 inhibition appeared to have a better effect. Finally, in the cancer cells of LUAD tumor samples, the KDF1 level was observed to correlate positively with the level of p-STAT3. All these findings suggest that KDF1, which activates STAT3 and the downstream AKT pathway in LUAD, acts as a tumor-promoting factor and may represent a therapeutic target.

The Significance of INHBE Expression in the Cancer Cells of Clear-Cell Renal Cell Carcinoma.

BACKGROUND: Activins and inhibins are structurally related dimeric glycoprotein hormones belonging to the transforming growth factor-ß superfamily but whether they are also involved in malignancy is far from clear. No study has reported the expression of INHBE in kidney cancer. The purpose of this study was to examine the expressions of INHBE in the tumor tissue of patients with clear-cell renal cell carcinoma (ccRCC) and to explore the pathologic significance. METHODS: The INHBE mRNA expression in the tumor tissue of ccRCC patients was analyzed by using RNA sequencing data from the TCGA database. To examine the expression of inhibin ßE protein, 241 ccRCC patients were recruited and immunohistochemistry was performed on the tumor tissue of these patients along with 39 normal renal samples. The association between the inhibin ßE expression level and patient's clinicopathological indices was evaluated. RESULTS: In the normal renal tissue, inhibin ßE was found to be expressed mainly by renal tubular epithelial cells. In the tumor tissue, inhibin ßE was expressed mainly in cancer cells. The expressions of INHBE mRNA and protein in the tumor tissue of ccRCC patients increased significantly compared with those in normal renal samples. There was a significant correlation between the level of inhibin ßE in the tumor tissue and tumor grade. Patients with a lower inhibin ßE expression in the tumor tissue were found to have a longer overall survival and disease-specific survival. CONCLUSIONS: INHBE might be involved in the pathogenesis of ccRCC and function as a tumor promoter.

By Increasing the Expression and Activation of STAT3, Sustained C5a Stimulation Increases the Proliferation, Migration, and Invasion of RCC Cells and Promotes the Growth of Transgrafted Tumors.

BACKGROUND: Contradictive results about the direct role of C5a/C5aR1 axis in different cancer cells have been reported. The direct effect of C5a on human renal cell carcinoma (RCC) cells and the underlying mechanism are not clear. The aim of this study is to investigate the role of C5a/C5aR1 axis in RCC cells and its working mechanism. METHODS: RCC cells were infected with lentivirus Lenti-C5a, which was designed to over-express secretory C5a in the cells, or directly treated with recombinant C5a, the influence of these treatments in the cells and the underlying mechanism were explored. RESULTS: Transfection of RCC cells with Lenti-C5a markedly increased the production of C5a and significantly increased the proliferation, migration, and invasion of RCC cells, but direct addition of C5a to the cell culture medium had no such effects though it indeed induced a transient intracellular calcium rise. RCC cells were found to express carboxypeptidase D and M, which reportedly to inactivate C5a. Also, the RCC cells stably transfected with Lenti-C5a produced larger transgrafted tumors in nude mice compared with the non-transfected or control virus transfected cells. In addition, over-expression of C5a significantly increased the expression and phosphorylation of STAT3 as well as the phosphorylated JNK level. Furthermore, the effect of C5a over-expression on RCC cells' proliferation, migration, and invasion could be blocked by Stattic, a STAT3-specific inhibitor. CONCLUSION: Chronic over-activation of C5a/C5aR1 axis could directly increase RCC cells' proliferation, migration, and invasion and thus contribute directly to the progression of the disease. Over-activation of STAT3 pathway is among the underlying mechanism.

KDF1, a Novel Tumor Suppressor in Clear Cell Renal Cell Carcinoma.

KDF1 has been identified as a key regulator of epidermal proliferation and differentiation, but it is unknown whether KDF1 is involved in the pathogenesis of malignancy. No study has reported the expression and function of KDF1 in renal cancer. To explore the pathologic significance of KDF1 in clear cell renal cell carcinoma (ccRCC), the expression level of KDF1 protein in the tumor tissue of ccRCC patients was examined by immunohistochemistry and Western blot while the expression level of KDF1 mRNA was analyzed by using the data from TCGA database. In vitro cell experiments and allogeneic tumor transplantation tests were performed to determine the effects of altered KDF1 expression on the phenotype of ccRCC cells. Both the KDF1 mRNA and protein were found to be decreasingly expressed in the tumor tissue of ccRCC patients when compared with the adjacent non-tumor control tissue. The expression level of KDF1 in the tumor tissue was found to correlate negatively with the tumor grade. Patients with higher KDF1 in the tumor tissue were found to have longer overall survival and disease-specific survival time. KDF1 was shown to be an independent factor influencing the disease-specific survival of the ccRCC patients. Overexpression of KDF1 was found to inhibit the proliferation, migration and invasion of ccRCC cells, which could be reversed by decreasing the expression of KDF1 again. ccRCC cells with KDF1 overexpression were found to produce smaller transgrafted tumors. These results support the idea that KDF1 is involved in ccRCC and may function as a tumor suppressor.

Sustained activation of C3aR in a human podocyte line impairs the morphological maturation of the cells.

The C3a receptor (C3aR) has been reported to be involved in various physiological and pathological processes, including the regulation of cellular structure development. Expression of C3aR has been reported in podocytes; however, data concerning the role of C3aR in podocyte morphology is scarce. The aim of the present study was to examine the effect of C3aR activation on the architectural development of podocytes. An immortal human podocyte line (HPC) was transfected with a C3a expression lentivirus vector or recombinant C3a. SB290157 was used to block the activation of C3aR. The expression of C3a in HPC cells was analyzed by reverse transcription­quantitative PCR (RT­qPCR) and ELISAs. Phase contrast and fluorescence microscopy were used to observe the morphology of the podocytes. The adhesive ability of HPC cells was analyzed using an attachment assay. RT­qPCR, cyto­immunofluorescence and western blotting were used to determine the expression levels of the adhesion­associated genes. The expression levels of carboxypeptidases in HPC cells was also detected by RT­qPCR. Compared with the untransfected and control virus­transfected HPC cells, the C3a­overexpressing cells (HPC­C3a) failed to expand their cell bodies and develop an arborized appearance in the process of maturation, which the control cells exhibited. In addition, HPC­C3a cells presented with decreased adhesive capacity, altered focal adhesion (FA) plaques and decreased expression of FA­associated genes. These effects were blocked by a C3aR antagonist; however, the addition of purified C3a could not completely mimic the effects of C3a overexpression. Furthermore, HPC cells expressed carboxypeptidases, which have been reported to be able to inactivate C3a. In summary, the results demonstrated that sustained C3aR activation impaired the morphological maturation of HPC cells, which may be associated with the altered expression of FA­associated genes and impaired FA. Since chronic complement activation has been reported in renal diseases, which indicate sustained C3aR activation in renal cells, including podocytes and podocyte progenitors, the possible role of C3aR in the dysregulation of podocyte architecture and podocyte regeneration requires further research.

Pathological significance of urinary complement activation in diabetic nephropathy: A full view from the development of the disease.

AIMS/INTRODUCTION: The aim of the present study was to obtain a full view of the changes of urinary complement activation products in the development of diabetic nephropathy and explore their possible significance in the disease process. MATERIALS AND METHODS: A total of 62 patients at different stages of diabetic nephropathy, 20 diabetes patients without nephropathy and 20 healthy persons were enrolled. Urinary complement activation products, including C3a, C5a and C5b-9, were measured, and their associations with the progression of the disease were analyzed. RESULTS: The urinary complement activation products increased markedly since the proteinuria stage, and were parallel with the progression of diabetic nephropathy. More severe renal tubular damage was observed in patients with higher levels of urinary complement activation products. The urinary complement activation products levels correlated closely with renal tubulointerstitial injury score and relative tubular interstitial volume. Multivariate regression analysis showed that elevated urinary complement activation products were independent risk factors for tubular injury in diabetic nephropathy patients. CONCLUSIONS: Urinary complement activation might have a role in renal tubular interstitial injury in patients with diabetic nephropathy, especially in patients at a later stage of the disease.

Lectin-induced renal local complement activation is involved in tubular interstitial injury in diabetic nephropathy.

BACKGROUND: Complement has been suggested to be involved in diabetic nephropathy (DN), but the exact significance and underlying mechanisms remain unclear. Data about renal local complement activation in DN patients is scarce. The purpose of the study was to clarify the significance and mechanism of renal local complement activation in DN. METHODS: Sixty-two biopsy-proven DN patients were recruited. Renal expression of C1Q, factor B, C5b-9, MBL and MBL-associated serine protease 1 (MASP1) were detected and associated with the kidney damage. RESULTS: C5b-9, MBL and MASP1 was found to increase with the progression of DN. Especially, the level of C5b-9, MBL and MASP1 in tubular interstitium was closely associated with the damage degree of tubular interstitium. In addition, MBL and MASP1 co-localized and their levels in tubular interstitium correlated with the levels of C5b-9 in tubules and tubular interstitium. CONCLUSION: Increased renal local complement activation was present in DN patients and might contribute to the kidney damage, especially tubular interstitial damage. MBL pathway might play an important role in renal tubular interstitial complement activation. Methods against complement activation or MBL pathway might be effective in reducing renal tubular interstitial damage in DN patients.

Rhein improves renal lesion and ameliorates dyslipidemia in db/db mice with diabetic nephropathy.

Rhein (4,5-dihydroxyanthraquinone-2-carboxylic acid) is purified from rhubarb (Rheum officinale), a widely used traditional Chinese herb. In our previous studies, rhein was shown to be effective in ameliorating diabetic renal pathological changes and attenuating hyperlipidemia. Statins have also been proven to ameliorate renal pathological changes associated with diabetic nephropathy (DN) through lipid-dependent and -independent mechanisms. We here study the protective and regulatory effects of rhein on renal injury and dyslipidemia in db/db mice with DN, using simvastatin as the control, and provide information on the mechanisms by which rhein protects against renal damage from DN. The results indicated that urinary albumin excretion (UAE) was reduced after 8 weeks of treatment in the rhein group, and 12 weeks in the simvastatin group. The morphometric analysis revealed that levels of extracellular matrix (ECM) significantly decreased in the rhein group after the full treatment course, but not in the simvastatin group. The more powerful effects of rhein on decreasing transforming growth factor-beta1 (TGF-beta1) and fibronectin immunohistochemistry expression in renal tissue were also observed. And the plasma levels of cholesterol (Chol), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C) and ApoE all decreased in both the rhein and the simvastatin groups. Together, our data suggested that both rhein and simvastatin regulate dyslipidemia. The powerful effect of rhein in renal protection is due to its widespread effects. Rhein is a new drug that can decrease lipid levels and protect against DN progression in a different fashion with simvastatin.

Clinicopathological and genetic characteristics in Chinese patients with lipoprotein glomerulopathy.

OBJECTIVE: In this study, we report on 16 Chinese patients with biopsy-proven lipoprotein glomerulopathy (LPG) investigated for clinical manifestations, pathological characteristics and apolipoprotein E (apoE) genetic analysis. METHODS: A retrospective analysis of the clinical and pathological features was made in 16 patients with LPG. Plasma concentrations and genetic analysis of apoE were completed. Glomerular depositions of apoA, apoB and apoE were detected using monoclonal antibodies on cryostatic sections in all patients. RESULTS: All 16 patients presented with edema; 14 presented with nephrotic syndrome. Anemia, microhematuria, hypertension and abnormal levels of serum creatinine were detected in 12 patients (75%), 11 patients (69%), 8 patients (50%) and 6 patients (37.5%), respectively. All the patients showed hypertriglyceridemia, while only 7 showed slight hypercholesterolemia. The characteristic features of hyperlipidemia in these patients were approximately in accord with those of type IV hyperlipoproteinemia. Concentrations of apoB correlated with urine protein, triglycerides and cholesterol (r=0.558, p=0.038; r=0.6, p=0.023; r=0.65, p=0.012; respectively). No correlation was found between serum level of apoE and clinicopathological features in patients with LPG. The genotype of apoE-epsilon3/epsilon4 is the predominant one in Chinese patients with LPG. No mutated forms of apoE were found, compared with previous reports. CONCLUSION: Unique clinicopathological and genetic features were found in this group of Chinese patients with LPG compared with the general population, including lower serum levels of apoE and cholesterol, as well as anemia and microhematuria. Multiple factors other than apoE were involved in the pathogenesis of LPG.

A complete genomic analysis of the apolipoprotein E gene in Chinese patients with lipoprotein glomerulopathy.

Mutations of the apolipoprotein E (apo E) gene are thought to play an etiological role in lipoprotein glomerulopathy (LPG), a novel kidney disease. Evidence suggesting that mutated forms of apo E may be present in LPG includes elevated plasma concentrations of apo E in LPG patients and deposition of apo E in their glomerular capillaries, and there are published reports indicating that mutations of the apo E gene are present in the Japanese LPG patient population. Conflicting reports, however, exist in the current literature. Therefore, to strengthen the theory that apo E gene mutations may be present in LPG pathogenesis, we chose to examine the 5.5 kb genomic DNA encompassing the entire apo E locus and adjoining flanking regions, in 17 Chinese LPG patients and 10 normal controls. Results suggest that there are no apo E gene mutations present in our LPG patients, including previously reported apo E mutations associated with LPG. Surprisingly, however, when the apo E sequence used in the current study was compared against the apo E gene sequence published in GenBank, 10 ethnic variation sites were identified in the noncoding regions. We therefore conclude that apo E gene mutations may not be the only etiology of LPG, and it is likely that other abnormalities could play a role in the pathogenesis of the disease.

Enhanced expression of ANGPTL2 in the microvascular lesions of diabetic glomerulopathy.

BACKGROUND: Diabetic nephropathy (DN) is one of the most important microvascular complications of diabetes mellitus. However, the underlying mechanisms remain unclear. We studied the expression characteristics of angiopoietin-like 2 (ANGPTL2), a novel DN-associated growth factor identified in our previous gene chip screening. METHODS: Glomeruli were microdissected from renal biopsies from 24 patients with DN and 8 donor controls. The expression of ANGPTL2 was assessed by RT-PCR and immunohistochemistry, and then correlated with clinical and pathological indices of glomerular injury. RESULTS: Consistent with the results of the gene chip experiment, abundant expression of ANGPTL2 was found more frequently in diabetic glomeruli as compared to donor controls (95 vs. 38%, chi(2) = 15.9, p < 0.01). ANGPTL2 mRNA upregulation was more prominent in glomeruli with less microaneurysm (22 vs. 66%, p < 0.05), inflammatory influx (6 vs. 50%, p < 0.05) or endothelial foam cell formation (11 vs. 53%, p < 0.05). Immunostaining revealed an upregulation of ANGPTL2 protein in hypertrophied diabetic glomeruli, mainly distributed in podocytes, which were supposed to be the origin of ANGPTL2. CONCLUSION: The upregulation of ANGPTL2 in diabetic glomerulopathy shows a close relationship to abnormal microvasculature and endothelial inflammation. ANGPTL2 may play an important role in the pathogenesis of diabetic glomerulopathy.

Influence of CYP3A5 and MDR1 polymorphisms on tacrolimus concentration in the early stage after renal transplantation.

OBJECTIVE: Tacrolimus is an immunosuppressive drug with a narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Cytochrome P450 (CYP) 3A and P-glycoprotein (P-gp, encoded by MDR1) play an important role in the absorption and metabolism of tacrolimus. The objective of this study was to evaluate whether or not CYP3A5*1/*3 or MDR1 C3435T polymorphisms are associated with the tacrolimus concentration per dose. METHODS: CYP3A5 and MDR1 genotypes were determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis in 118 Chinese renal transplant patients receiving tacrolimus. Whole blood trough tacrolimus concentration was measured by enzyme-linked immunosorbent assay and dose-adjusted concentration (ng/mL per mg/kg/d) was calculated at 1 wk, 1 month, and 3 months after transplantation. RESULTS: The dose-adjusted concentration of CYP3A5*1/*1 and *1/*3 patients was significantly lower than *3/*3 patients (32.8 +/- 17.7 and 41.6 +/- 15.8 vs. 102.3 +/- 51.2 at 1 wk; 33.1 +/- 7.5 and 46.4 +/- 12.9 vs. 103 +/- 47.5 at 1 month; 35.3 +/- 20.9 and 59.0 +/- 20.6 vs. 150 +/- 85.3 at 3 months after transplantation respectively). At 1 wk, 46% of the CYP3A5*1 allele carriers had a tacrolimus concentration lower than 5 ng/mL and 77% lower than 8 ng/mL, whereas 20% of the *3/*3 patients had a concentration higher than 20 ng/mL. There was a mild difference between *1/*1 homozygotes and *1/*3 heterozygotes at 1 and 3 months after transplantation. No difference was found among the MDR1 genotypes. CONCLUSION: CYP3A5*1/*3 polymorphisms are associated with tacrolimus pharmacokinetics and dose requirements in renal transplant recipients. Pharmacogenetic methods could be employed prospectively to help initial dose selection and to individualize immunosuppressive therapy.

Plasma level and genetic variation of apolipoprotein E in patients with lipoprotein glomerulopathy.

BACKGROUND: Lipoprotein glomerulopathy (LPG) is a renal disease characterized by thrombus-like lipoproteins in the glomerular capillaries and its abnormal lipoprotein profiles with marked elevation of apolipoprotein E (apoE). In this study, 15 Chinese patients with LPG were involed in exploring the association of the genetic variation and its plasma level in the pathogenesis of LPG. METHODS: A retrospective analysis of the clinical and pathological features was made in 15 patients with LPG. Plasma concentrations of apoE were measured with radial immunodiffusion assay. Genetic variations of apoE gene were detected using polymerase chain reaction and restriction fragment length polymorphism. Glomerular deposition of apoA, apoB and apoE in these patients were detected by immunofluorescence staining using monoclonal antibodies. RESULTS: Biochemical profiles of lipids and lipoproteins revealed markedly elevated levels of triglyceride, apoB and apoE, but approximately normal levels of total cholesterol, apoA1 and lipoprotein(a) [Lp(a)], which resembled familial hypertriglyceridemia. Genetic analysis demonstrated that the genotype distribution of apoE were 7 cases with epsilon3/epsilon4, 4 cases with epsilon3/epsilon3 and 2 cases with epsilon2/epsilon3. The other 2 cases (a mother and her son) showed a same distinct band. The band pattern of later 2 cases was quite similar to the apoE variant of Tokyo type. The calculated allele frequency of epsilon 4 was relatively high in cases with LPG in comparison with that in the normal controls. We further divided the 13 patients into three groups according to their genotypes of apoE. Patients with the genotype of apoE epsilon2/epsilon3 showed a lower level of plasma apoE as compared to those with apoE epsilon3/epsilon4 (P < 0.05). The serum level of high-density lipoprotein (HDL) was the lowest in patients with the genotype of apoE epsilon3/epsilon4. No difference was found among the patients with different apoE genotype in the other clinical and pathological characteristics. CONCLUSIONS: The genotype of apoE epsilon3/epsilon4 is the predominant one in Chinese patients with LPG. Patients with this genotype tend to have a higher plasma level of apoE and more severe lipid dysmetabolism. No correlation was found between the genotype of apoE and the clinical features in patients with LPG.