Differential expression of HIF1A and its downstream target VEGFA in the main subtypes of renal cell carcinoma and their impact on patient survival.

Renal cell carcinoma (RCC) represents around 3% of all cancers, with the most frequent histological types being clear-cell RCC (ccRCC), followed by papillary (pRCC) and chromophobe (chRCC). Hypoxia-inducible factors (HIFs), which promote the expression of various target genes, including vascular endothelial growth factor (VEGF) and the high- affinity glucose transporter 1, have an important role in the pathogenesis of RCC. This study investigated the immunohistochemical expression of HIF-1α and VEGF-A, showing significantly higher HIF-1α nuclear expression in pRCC compared to ccRCC, while there was no significant difference in VEGF-A protein expression between the analyzed histological RCC subtypes. The quantitative reverse transcription polymerase chain reaction for HIF1A showed no statistical difference between histological types. Data from publicly available RNA sequencing databases were analyzed and showed that, compared to healthy kidney tissue, VEGFA was significantly up-regulated in ccRCC and significantly down-regulated in pRCC. The comparison between histological subtypes of RCC revealed that VEGFA was significantly up-regulated in ccRCC compared to both pRCC and chRCC. There was no statistically significant difference in survival time between HIF1A high- and low-expression groups of patients. As for VEGFA expression, pRCC patients with low expression had a significantly higher survival rate compared to patients with high VEGFA expression.

Determining the immunohistochemical expression of GLUT1 in renal cell carcinoma using the HSCORE method.

The aim of the present study was to compare the immunohistochemical expression of glucose transporter 1 (GLUT1) between the most common histological types of renal cell carcinoma (RCC), and to determine whether a correlation between GLUT1 expression and nuclear grade or tumor size exists. A total of 19 RCC samples were selected for the study, consisting of 8 clear cell (cc)RCC and 11 non-ccRCC tissues. Immunohistochemistry for GLUT1 was performed on formalin-fixed and paraffin-embedded sections using GLUT1 antibodies. All data analyses were performed using the MedCalc software. There was a higher immunohistochemical expression of GLUT1 in the ccRCC group compared with the non-cc group, but there was no difference in GLUT1 expression between groups of RCCs with differing nuclear grades. No significant correlation between GLUT1 expression and tumor size was found. The higher immunohistochemical expression of GLUT1 in ccRCC may be a contributing factor to the clinical characteristics and behavior of that group of carcinomas. These results suggest that GLUT1 expression cannot be used as a prognostic factor for RCC, but it may be used as a predictive factor in the future.

Immunohistochemical expression pattern of RIP5, FGFR1, FGFR2 and HIP2 in the normal human kidney development.

AIM: Present study analyses the co-localisation of RIP5 with FGFR1, FGFR2 and HIP2 in the developing kidney, as RIP5 is a major determinant of urinary tract development, downstream of FGF-signaling. METHODS: Paraffin embedded human kidney tissues of 16 conceptuses between the 6th-22th developmental week were analysed using double-immunofluorescence method with RIP5/FGFR1/FGFR2 and HIP2 markers. Quantification of positive cells were performed using Kruskal-Wallis test. RESULTS: In the 6th week of kidney development RIP5 (89.6%) and HIP2 (39.6%) are strongly expressed in the metanephric mesenchyme. FGFR1 shows moderate/strong expression in the developing nephrons (87.3%) and collecting ducts (70.5%) (p < 0.05). RIP5/FGFR1 co-localized at the marginal zone and the ureteric bud with predominant FGFR1 expression. FGFR2 (26.1%) shows similar expression pattern as FGFR1 (70.5%) in the same kidney structures. RIP5/FGFR2 co-localized at the marginal zone and the collecting ducts (predominant expression of FGFR2). HIP2 is strongly expressed in collecting ducts (96.7%), and co-localized with RIP5. In 10th week, RIP5 expression decrease (74.2%), while the pattern of expression of RIP5 and FGFR1 in collecting ducts (33.4% and 91.9%) and developing nephrons (21.9% and 32.4%) (p < 0.05) is similar to that in the 6th developmental week. Ureter is moderately expressing RIP5 while FGFR1 is strongly expressed in the ureteric wall. FGFR2 is strongly expressed in the collecting ducts (84.3%) and ureter. HIP2 have 81.1% positive cells in the collecting duct. RIP5/FGFR1 co-localize in collecting ducts and Henley's loop. CONCLUSIONS: The expression pattern of RIP5, FGFR1, FGFR2 and HIP2 in the human kidney development might indicate their important roles in metanephric development and ureteric muscle layer differentiation through FGF signaling pathways.

Expression of EGF, EGFR, and proliferation in placentas from pregnancies complicated with preeclampsia.

OBJECTIVE: To investigate proliferation, EGF and EGFR expression of villous trophoblast (VTB), decidual cells (DC), and extravillous trophoblast (EVTB) in the placentas from pregnancies complicated with preeclampsia (PE) and to compare them with placentas from normal pregnancies. METHODS: Twenty-nine PE placentas and 19 control placentas were studied for EGF and EGFR immunohistochemical expression (noted as week, moderate or strong). Proliferation was expressed as the proliferation index. The CK7 antibody was used to distinguish DC from EVTB. RESULTS: DC and EVTB proliferation was significantly higher in PE placentas. EGFR and EGF expression showed no significant difference. CONCLUSION: Higher DC and EVTB proliferation in PE could contribute to PE development.

Expression of inflammatory cytokines in placentas from pregnancies complicated with preeclampsia and HELLP syndrome.

OBJECTIVE: To investigate the expression of tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and interleukin-10 (IL-10) in villous trophoblast, syncytial knots and decidua placentas from pregnancies complicated with preeclampsia (PE), Hemolysis, Elevated Liver enzymes and Low Platelet count (HELLP) syndrome and gestational age-matched controls. METHODS: Study group included 35 placentas from pregnancies complicated with PE and 35 placentas from pregnancies with HELLP syndrome. Control group included 35 placentas from idiopathic preterm labor. Placentas were matched according to the gestational age. Expression of TNF-α, IL-6 and IL-10 was determined by immunohistochemistry and semi-quantitative HSCORE method in villous trophoblast, syncytial knots and decidua. Non-parametric statistics were used for analyses. RESULTS: There was no difference in the expression of TNF-α, IL-6 and IL-10 in all the studied placental segments between PE, HELLP and gestational age-matched control group. TNF-α (F = 32, 41, p < 0.001), IL-6 (F = 58, 53, p < 0.001) and IL-10 (F = 17, 62, p < 0.001) expression was significantly different in different placental cell types, the highest expression of cytokines was in decidua. CONCLUSION: There was no difference in cytokine expression in villous trophoblast, syncytial knots and decidua among the studied placental groups. The expression of cytokines was highest in decidua in all the studied placental groups.

Trophoblast apoptosis in human term placentas from pregnancies complicated with idiopathic intrauterine growth retardation.

OBJECTIVE: To investigate proliferative, apoptotic, and antiapoptotic activity of placental trophoblast in pregnancies complicated with idiopathic intrauterine growth retardation (IUGR). METHODS: Study group included data and placentas from 52 normal singleton term pregnancies with idiopathic IUGR. Records and placentas from 69 singleton pregnancies with normal fetal growth served as a control group. IUGR was defined by birth weight less than 10th percentile of standard values. Children with congenital malformations and those born with the signs of hypoxia, laboratory or clinical signs of preeclampsia or infection, children born to anemic mothers and those born from pregnancies with an increased coagulation system activity were excluded. RESULTS: There was no statistically significant difference in the cytotrophoblast proliferation index value (Z = 0.24; P = 0.553), trophoblast expression of the Bcl-2 antiapoptotic factor (Z = 0.47; P = 0.634), and trophoblast apoptotic index (Z = 0.51; P = 0.613) between the idiopathic IUGR and control group. CONCLUSION: The proliferative and apoptotic events in the trophoblast of placentas with idiopathic IUGR did not differ from physiologic ones. Study results suggest the IUGR syndrome to have no uniform etiology or even underlying pathophysiology that would determine the possible fetal risk and subsequent long-term consequences for fetal health and life. This imposes the need of a more precise definition and unambiguous distinction between the idiopathic and other forms of IUGR.

Morphological characteristics of placentas associated with idiopathic intrauterine growth retardation: a clinicopathologic study.

OBJECTIVES: To investigate histopathologic findings, placental diameters and characteristics of syncytial knots in the placentas from idiopathic intrauterine growth retardation (IUGR) pregnancies, and to compare them with a normal birth weight group. STUDY DESIGN: Based on strict eligibility criteria, this prospective case-control study included 52 term placentas from idiopathic IUGR pregnancies and 69 term placentas from normal birth weight pregnancies. The study was carried out at the Clinical Hospital Centre, Split, where all placentas were collected and examined. For each placenta, diameters were measured and the following histopathologic findings were recorded: infarction, intervillous thrombosis, abruption, villous branching and maturation, chorioamnionitis, decidual vasculopathy and hemorrhagic endovasculitis for each placenta. In addition we assessed quantitative (number of syncytial knots and number of syncytial nuclei per syncytial knot) and qualitative (density and surface area) characteristics of syncytial knots in each placental sample. Statistical significance was tested using chi(2)-test, Student's t-test and Mann-Whitney U-test. Statistical significance was set at P< or =0.05. RESULTS: There was no difference in investigated histopathologic findings between idiopathic IUGR placentas and control group placentas. Placental diameters correlated significantly with neonatal birth weight (r=0.64; P<0.01); with higher birth weight there is an increase in placental diameters. Syncytial knots from idiopathic IUGR had significantly smaller surface area (Z=2.637; P=0.008) and higher density (Z=3.225; P=0.001) compared with the control group, while there is no difference in number of syncytial knots per individual villus, total number of syncytial knots in each placenta sample or number of syncytial nuclei per syncytial knot. CONCLUSIONS: The investigated histopathologic findings in idiopathic IUGR placentas are incidental, with no higher frequency than in placentas from uncomplicated pregnancies, and should not be considered as possible causative factors for idiopathic IUGR. The demonstrated qualitative changes of syncytial knots in placentas associated with IUGR could represent a compensatory mechanism.