Proteomic changes in the human cerebrovasculature in Alzheimer's disease and related tauopathies linked to peripheral biomarkers in plasma and cerebrospinal fluid.

INTRODUCTION: Cerebrovascular dysfunction is a pathological hallmark of Alzheimer's disease (AD). Nevertheless, detecting cerebrovascular changes within bulk tissues has limited our ability to characterize proteomic alterations from less abundant cell types. METHODS: We conducted quantitative proteomics on bulk brain tissues and isolated cerebrovasculature from the same individuals, encompassing control (N = 28), progressive supranuclear palsy (PSP) (N = 18), and AD (N = 21) cases. RESULTS: Protein co-expression network analysis identified unique cerebrovascular modules significantly correlated with amyloid plaques, cerebrovascular amyloid angiopathy (CAA), and/or tau pathology. The protein products within AD genetic risk loci were concentrated within cerebrovascular modules. The overlap between differentially abundant proteins in AD cerebrospinal fluid (CSF) and plasma with cerebrovascular network highlighted a significant increase of matrisome proteins, SMOC1 and SMOC2, in CSF, plasma, and brain. DISCUSSION: These findings enhance our understanding of cerebrovascular deficits in AD, shedding light on potential biomarkers associated with CAA and vascular dysfunction in neurodegenerative diseases.

Proteomic Changes in the Human Cerebrovasculature in Alzheimer's Disease and Related Tauopathies Linked to Peripheral Biomarkers in Plasma and Cerebrospinal Fluid.

Dysfunction of the neurovascular unit stands as a significant pathological hallmark of Alzheimer's disease (AD) and age-related neurodegenerative diseases. Nevertheless, detecting vascular changes in the brain within bulk tissues has proven challenging, limiting our ability to characterize proteomic alterations from less abundant cell types. To address this challenge, we conducted quantitative proteomic analyses on both bulk brain tissues and cerebrovascular-enriched fractions from the same individuals, encompassing cognitively unimpaired control, progressive supranuclear palsy (PSP), and AD cases. Protein co-expression network analysis identified modules unique to the cerebrovascular fractions, specifically enriched with pericytes, endothelial cells, and smooth muscle cells. Many of these modules also exhibited significant correlations with amyloid plaques, cerebral amyloid angiopathy (CAA), and/or tau pathology in the brain. Notably, the protein products within AD genetic risk loci were found concentrated within modules unique to the vascular fractions, consistent with a role of cerebrovascular deficits in the etiology of AD. To prioritize peripheral AD biomarkers associated with vascular dysfunction, we assessed the overlap between differentially abundant proteins in AD cerebrospinal fluid (CSF) and plasma with a vascular-enriched network modules in the brain. This analysis highlighted matrisome proteins, SMOC1 and SMOC2, as being increased in CSF, plasma, and brain. Immunohistochemical analysis revealed SMOC1 deposition in both parenchymal plaques and CAA in the AD brain, whereas SMOC2 was predominantly localized to CAA. Collectively, these findings significantly enhance our understanding of the involvement of cerebrovascular abnormalities in AD, shedding light on potential biomarkers and molecular pathways associated with CAA and vascular dysfunction in neurodegenerative diseases.

CD4, CD20 and PD-L1 as Markers of Recurrence in Non-Muscle-Invasive Bladder Cancer.

INTRODUCTION: A tumor microenvironment plays an important role in bladder cancer development and in treatment response. PURPOSE: The aim of the study was to assess how the components of the microenvironment affect tumor recurrence and to find the potential biomarkers for immunotherapy in NMIBC. METHODS: The study group consisted of 55 patients with primary NMIBC. Immunohistochemistry was performed on sections of primary papillary urothelial carcinoma of the bladder. Cox proportional hazard multiple regression analysis was performed to characterize tumors with the highest probability of an unfavorable outcome. RESULTS: Multivariate analysis confirmed that the CD4 (p = 0.001), CD20 (p = 0.008) and PD-L1 expressed on tumor cells (p = 0.01) were independently associated with the risk of recurrence of bladder cancer. Patients with weak CD4+ cell infiltration (<4.6%) and severe CD20+ infiltration (>10%) belong to the group with a lower risk of recurrence. The cancer in this group also frequently recurs after 12 months (p = 0.0005). CONCLUSIONS: The evaluation of CD4+ and CD20+ cells in the tumor microenvironment, in addition to PD-L1 on tumor cells, facilitates the determination of a group of patients with a low risk of recurrence.

Tumour microenvironment as a predictive factor for immunotherapy in non-muscle-invasive bladder cancer.

Bladder cancer (BC) can be divided into two subgroups depending on invasion of the muscular layer: non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC). Its aggressiveness is associated, inter alia, with genetic aberrations like losses of 1p, 6q, 9p, 9q and 13q; gain of 5p; or alterations in the p53 and p16 pathways. Moreover, there are reported metabolic disturbances connected with poor diagnosis-for example, enhanced aerobic glycolysis, gluconeogenesis or haem catabolism.Currently, the primary way of treatment method is transurethral resection of the bladder tumour (TURBT) with adjuvant Bacillus Calmette-Guérin (BCG) therapy for NMIBC or radical cystectomy for MIBC combined with chemotherapy or immunotherapy. However, intravesical BCG immunotherapy and immune checkpoint inhibitors are not efficient in every case, so appropriate biomarkers are needed in order to select the proper treatment options. It seems that the success of immunotherapy depends mainly on the tumour microenvironment (TME), which reflects the molecular disturbances in the tumour. TME consists of specific conditions like hypoxia or local acidosis and different populations of immune cells including tumour-infiltrating lymphocytes, natural killer cells, neutrophils and B lymphocytes, which are responsible for shaping the response against tumour neoantigens and crucial pathways like the PD-L1/PD-1 axis.In this review, we summarise holistically the impact of the immune system, genetic alterations and metabolic changes that are key factors in immunotherapy success. These findings should enable better understanding of the TME complexity in case of NMIBC and causes of failures of current therapies.

Malignancy Prevalence in the Dialyzed Population and in Waitlisted Potential Kidney Transplant Recipients.

Malignancy is the second cause of death in the dialyzed population. However, data on the prevalence of cancer are very scarce. Kidney transplantation improves quality of life, prolongs survival, and is cost-effective but bears some serious complications including malignancy. Therefore, active screening for cancer is of utmost importance. The aim of this study was to assess the prevalence of malignancy in dialyzed patients in relation to status on the on the waiting list and type of dialysis. This cross-sectional study was conducted in 108 hemodialyzed patients (mean age 65 years, 47 women) and 47 peritoneally dialyzed patients (mean age 51 years, 25 women). Among the population studied, 20 patients were actively waitlisted, including 14 peritoneal dialysis patients. Patients who had been active on the cadaver kidney waiting list and not listed did not differ in regard to sex, dialysis vintage, and causes of end-stage renal failure, but were significantly younger. Among hemodialysis patients, 24 of them had a history of malignancy and 10 in the peritoneal dialysis population. The most common were renal cell carcinoma in 6, breast cancer in 4, lung cancer in 3, prostate cancer in 3, hepatocellular cancer in 2, colorectal cancer in 2, esophageal cancer in 2, and others 14. In waitlisted patients, only 2 hemodialysis patients had a history of malignancy. Waitlisted patients represent a very selected and healthier dialyzed population. Malignancy has become a more common comorbidity in dialyzed patients, which may have important clinical implication regarding therapy. Guidelines for cancer screening in potential transplant recipients should be developed, as nowadays there are scarcity of data in this matter.

Oncometabolites-A Link between Cancer Cells and Tumor Microenvironment.

The tumor microenvironment is the space between healthy tissues and cancer cells, created by the extracellular matrix, blood vessels, infiltrating cells such as immune cells, and cancer-associated fibroblasts. These components constantly interact and influence each other, enabling cancer cells to survive and develop in the host organism. Accumulated intermediate metabolites favoring dysregulation and compensatory responses in the cell, called oncometabolites, provide a method of communication between cells and might also play a role in cancer growth. Here, we describe the changes in metabolic pathways that lead to accumulation of intermediate metabolites: lactate, glutamate, fumarate, and succinate in the tumor and their impact on the tumor microenvironment. These oncometabolites are not only waste products, but also link all types of cells involved in tumor survival and progression. Oncometabolites play a particularly important role in neoangiogenesis and in the infiltration of immune cells in cancer. Oncometabolites are also associated with a disrupted DNA damage response and make the tumor microenvironment more favorable for cell migration. The knowledge summarized in this article will allow for a better understanding of associations between therapeutic targets and oncometabolites, as well as the direct effects of these particles on the formation of the tumor microenvironment. In the future, targeting oncometabolites could improve treatment standards or represent a novel method for fighting cancer.

Widespread choroid plexus contamination in sampling and profiling of brain tissue.

The choroid plexus, a tissue responsible for producing cerebrospinal fluid, is found predominantly in the lateral and fourth ventricles of the brain. This highly vascularized and ciliated tissue is made up of specialized epithelial cells and capillary networks surrounded by connective tissue. Given the complex structure of the choroid plexus, this can potentially result in contamination during routine tissue dissection. Bulk and single-cell RNA sequencing studies, as well as genome-wide in situ hybridization experiments (Allen Brain Atlas), have identified several canonical markers of choroid plexus such as Ttr, Folr1, and Prlr. We used the Ttr gene as a marker to query the Gene Expression Omnibus database for transcriptome studies of brain tissue and identified at least some level of likely choroid contamination in numerous studies that could have potentially confounded data analysis and interpretation. We also analyzed transcriptomic datasets from human samples from Allen Brain Atlas and the Genotype-Tissue Expression (GTEx) database and found abundant choroid contamination, with regions in closer proximity to choroid more likely to be impacted such as hippocampus, cervical spinal cord, substantia nigra, hypothalamus, and amygdala. In addition, analysis of both the Allen Brain Atlas and GTEx datasets for differentially expressed genes between likely "high contamination" and "low contamination" groups revealed a clear enrichment of choroid plexus marker genes and gene ontology pathways characteristic of these ciliated choroid cells. Inclusion of these contaminated samples could result in biological misinterpretation or simply add to the statistical noise and mask true effects. We cannot assert that Ttr or other genes/proteins queried in targeted assays are artifacts from choroid contamination as some of these differentials may be due to true biological effects. However, for studies that have an unequal distribution of choroid contamination among groups, investigators may wish to remove contaminated samples from analyses or incorporate choroid marker gene expression into their statistical modeling. In addition, we suggest that a simple RT-qPCR or western blot for choroid markers would mitigate unintended choroid contamination for any experiment, but particularly for samples intended for more costly omic profiling. This study highlights an unexpected problem for neuroscientists, but it is also quite possible that unintended contamination of adjacent structures occurs during dissections for other tissues but has not been widely recognized.

Clusterin ameliorates tau pathology in vivo by inhibiting fibril formation.

The molecular chaperone Clusterin (CLU) impacts the amyloid pathway in Alzheimer's disease (AD) but its role in tau pathology is unknown. We observed CLU co-localization with tau aggregates in AD and primary tauopathies and CLU levels were upregulated in response to tau accumulation. To further elucidate the effect of CLU on tau pathology, we utilized a gene delivery approach in CLU knock-out (CLU KO) mice to drive expression of tau bearing the P301L mutation. We found that loss of CLU was associated with exacerbated tau pathology and anxiety-like behaviors in our mouse model of tauopathy. Additionally, we found that CLU dramatically inhibited tau fibrilization using an in vitro assay. Together, these results demonstrate that CLU plays a major role in both amyloid and tau pathologies in AD.

Astrocyte-derived clusterin suppresses amyloid formation in vivo.

BACKGROUND: Accumulation of amyloid-ß (Aß) peptide in the brain is a pathological hallmark of Alzheimer's disease (AD). The clusterin (CLU) gene confers a risk for AD and CLU is highly upregulated in AD patients, with the common non-coding, protective CLU variants associated with increased expression. Although there is strong evidence implicating CLU in amyloid metabolism, the exact mechanism underlying the CLU involvement in AD is not fully understood or whether physiologic alterations of CLU levels in the brain would be protective. RESULTS: We used a gene delivery approach to overexpress CLU in astrocytes, the major source of CLU expression in the brain. We found that CLU overexpression resulted in a significant reduction of total and fibrillar amyloid in both cortex and hippocampus in the APP/PS1 mouse model of AD amyloidosis. CLU overexpression also ameliorated amyloid-associated neurotoxicity and gliosis. To complement these overexpression studies, we also analyzed the effects of haploinsufficiency of Clu using heterozygous (Clu+/-) mice and control littermates in the APP/PS1 model. CLU reduction led to a substantial increase in the amyloid plaque load in both cortex and hippocampus in APP/PS1; Clu+/- mice compared to wild-type (APP/PS1; Clu+/+) littermate controls, with a concomitant increase in neuritic dystrophy and gliosis. CONCLUSIONS: Thus, both physiologic ~ 30% overexpression or ~ 50% reduction in CLU have substantial impacts on amyloid load and associated pathologies. Our results demonstrate that CLU plays a major role in Aß accumulation in the brain and suggest that efforts aimed at CLU upregulation via pharmacological or gene delivery approaches offer a promising therapeutic strategy to regulate amyloid pathology.

Selected protein expression in a new prognostic model for patients with non-muscle-invasive bladder cancer.

INTRODUCTION: After transurethral resection of a bladder tumor, patients frequently have a recurrence of the disease, thereby requiring adjuvant therapy. PURPOSE: The study aimed to determine the prognostic value of expression levels of p53, Ki-67, and survivin, and to develop a new prognostic model for patients with non-muscle-invasive bladder cancer (NMIBC) after transurethral resection of a bladder tumor. METHODS: The study group consisted of 101 patients with primary NMIBC. Univariate followed by multivariate Cox proportional hazard regression analysis was performed to obtain a model including the smallest possible number of descriptive variables with the highest statistical significance and impact on risk. RESULTS: The RECINT model (RECurrence In Not Treated) including factors independently associated with cancer recurrence (tumor size [HR 1.148; p = 0.034], intensity of the color reaction for p53 [HR 1.716; p = 0.008], Ki-67 [HR 3.001; p = 0.022], and survivin [HR 1.461; p = 0.021]) adequately stratified recurrence free-survival (R2 = 0.341, p < 0.001) in patients with primary NMIBC. Patients with the lowest RECINT score (0-6) had the lowest probability of cancer recurrence (1- and 5-year recurrence of 16%) in comparison with other groups (p < 0.001). CONCLUSIONS: The RECINT model may be useful for stratifying the risk of recurrence in patients with non-muscle-invasive bladder cancer and may allow for identification of those who may benefit the most from adjuvant BCG immunotherapy.

Intensity of Nuclear Staining for Ki-67, p53 and Survivin as a New Prognostic Factor in Non-muscle Invasive Bladder Cancer.

The aim of the study was to determine the prognostic value of expression levels of biomarkers selected on the basis of the literature: p53, Ki-67, survivin, ß-catenin, E-cadherin and N-cadherin in patients with non-muscle invasive bladder cancer. Immunohistochemistry was performed on sections of primary papillary carcinoma of the bladder removed during transurethral resection of the tumor in 134 patients. The expression of ß-catenin and E-cadherin was found in all analyzed cases and N-cadherin expression was demonstrated in 3.73% of the tissues examined. The expression of the p53 protein was confirmed in 96.27% of tissues examined. The expression of the Ki-67 protein was demonstrated in all analyzed cases. Survivin expression was found in 95.52% of the study group. Multivariate analysis confirmed the relationship between the recurrence-free survival (RFS) and the intensity of the nuclear reaction for p53 (HR 1417, 95% CI 1.001-2.007, p = 0.049) and survivin (HR 1.451; 95% CI 1.078-1.955; p = 0.014), the expression level of the Ki-67 protein expressed by the TS index (HR 1.146, 95% CI 1.116-1.823, p = 0.005) and the use of adjuvant BCG therapy (HR 0.218, 95% CI 0.097-0.489, p = 0.0002). The evaluation of Ki-67 expression and the intensity of nuclear staining for survivin and p53 may provide additional information that will allow more accurate stratification of the risk of NMIBC recurrence after TURBT.

Neutrophil-to-lymphocyte Ratio, Platelet-to-lymphocyte Ratio, and C-reactive Protein as New and Simple Prognostic Factors in Patients With Metastatic Renal Cell Cancer Treated With Tyrosine Kinase Inhibitors: A Systemic Review and Meta-analysis.

BACKGROUND: Inflammation plays a crucial role in cancer development. In this study, we evaluate the prognostic values of systemic inflammation markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and C-reactive protein (CRP) for the progression-free survival and overall survival in patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitors. MATERIALS AND METHODS: PubMed and the Cochrane Library databases were searched for published studies on the effect of NLR, PLR, and CRP in patients with metastatic renal cell carcinoma treated with tyrosine kinase inhibitors. RESULTS: In the meta-analysis, NLR (hazard ratio [HR], 2.01; 95% confidence interval [CI], 1.27-3.18; P = .003) and PLR (HR, 6.96; 95% CI, 5.04-9.62; P < .001) had a significant influence on progression-free survival, whereas all considered proinflammatory markers had a significant impact on overall survival: NLR (HR, 2.14; 95% CI, 1.67-2.73; P < .001), PLR (HR, 14.67; 95% CI, 11.10-19.57; P < .001), and CRP (HR, 1.96; 95% CI, 1.26-3.05; P = .003). CONCLUSIONS: Inflammation markers such as NLR, PLR, and CRP are predictors of clinical outcome and could provide additional information to individualize treatment.

Loss of clusterin shifts amyloid deposition to the cerebrovasculature via disruption of perivascular drainage pathways.

Alzheimer's disease (AD) is characterized by amyloid-ß (Aß) peptide deposition in brain parenchyma as plaques and in cerebral blood vessels as cerebral amyloid angiopathy (CAA). CAA deposition leads to several clinical complications, including intracerebral hemorrhage. The underlying molecular mechanisms that regulate plaque and CAA deposition in the vast majority of sporadic AD patients remain unclear. The clusterin (CLU) gene is genetically associated with AD and CLU has been shown to alter aggregation, toxicity, and blood-brain barrier transport of Aß, suggesting it might play a key role in regulating the balance between Aß deposition and clearance in both brain and blood vessels. Here, we investigated the effect of CLU on Aß pathology using the amyloid precursor protein/presenilin 1 (APP/PS1) mouse model of AD amyloidosis on a Clu+/+ or Clu-/- background. We found a marked decrease in plaque deposition in the brain parenchyma but an equally striking increase in CAA within the cerebrovasculature of APP/PS1;Clu-/- mice. Surprisingly, despite the several-fold increase in CAA levels, APP/PS1;Clu-/- mice had significantly less hemorrhage and inflammation. Mice lacking CLU had impaired clearance of Aß in vivo and exogenously added CLU significantly prevented Aß binding to isolated vessels ex vivo. These findings suggest that in the absence of CLU, Aß clearance shifts to perivascular drainage pathways, resulting in fewer parenchymal plaques but more CAA because of loss of CLU chaperone activity, complicating the potential therapeutic targeting of CLU for AD.

Influence of Tyrosine Kinase Inhibitors on Hypertension and Nephrotoxicity in Metastatic Renal Cell Cancer Patients.

Renal cell carcinoma (RCC) is one of the most common kidney malignancies. An upgraded comprehension of the molecular biology implicated in the development of cancer has stimulated an increase in research and development of innovative antitumor therapies. The aim of the study was to analyze the medical literature for hypertension and renal toxicities as the adverse events of the vascular endothelial growth factor (VEGF) signaling pathway inhibitor (anti-VEGF) therapy. Relevant studies were identified in PubMed and ClinicalTrials.gov databases. Eligible studies were phase III and IV prospective clinical trials, meta-analyses and retrospective studies that had described events of hypertension or nephrotoxicity for patients who received anti-VEGF therapy. A total of 48 studies were included in the systematic review. The incidence of any grade hypertension ranged from 17% to 49.6%. Proteinuria and increased creatinine levels were ascertained in 8% to 73% and 5% to 65.6% of patients, respectively. These adverse events are most often mild in severity but may sometimes lead to treatment discontinuation. Nephrotoxicity and hypertension are related to multiple mechanisms; however, one of the main disturbances in those patients is VEGF inhibition. There is a significant risk of developing hypertension and renal dysfunction among patients receiving anti-VEGF treatment; however, there is also some evidence that these side effects may be used as biomarkers of response to antiangiogenic agents.

Prosaposin is a regulator of progranulin levels and oligomerization.

Progranulin (GRN) loss-of-function mutations leading to progranulin protein (PGRN) haploinsufficiency are prevalent genetic causes of frontotemporal dementia. Reports also indicated PGRN-mediated neuroprotection in models of Alzheimer's and Parkinson's disease; thus, increasing PGRN levels is a promising therapeutic for multiple disorders. To uncover novel PGRN regulators, we linked whole-genome sequence data from 920 individuals with plasma PGRN levels and identified the prosaposin (PSAP) locus as a new locus significantly associated with plasma PGRN levels. Here we show that both PSAP reduction and overexpression lead to significantly elevated extracellular PGRN levels. Intriguingly, PSAP knockdown increases PGRN monomers, whereas PSAP overexpression increases PGRN oligomers, partly through a protein-protein interaction. PSAP-induced changes in PGRN levels and oligomerization replicate in human-derived fibroblasts obtained from a GRN mutation carrier, further supporting PSAP as a potential PGRN-related therapeutic target. Future studies should focus on addressing the relevance and cellular mechanism by which PGRN oligomeric species provide neuroprotection.

Identification of plexin A4 as a novel clusterin receptor links two Alzheimer's disease risk genes.

Although abundant genetic and biochemical evidence strongly links Clusterin (CLU) to Alzheimer disease (AD) pathogenesis, the receptor for CLU within the adult brain is currently unknown. Using unbiased approaches, we identified Plexin A4 (PLXNA4) as a novel, high-affinity receptor for CLU in the adult brain. PLXNA4 protein expression was high in brain with much lower levels in peripheral organs. CLU protein levels were significantly elevated in the cerebrospinal fluid (CSF) of Plxna4-/- mice and, in humans, CSF levels of CLU were also associated with PLXNA4 genotype. Human AD brains had significantly increased the levels of CLU protein but decreased levels of PLXNA4 by ∼50%. To determine whether PLXNA4 levels influenced cognition, we analyzed the behaviour of Plxna4+/+, Plxna4+/-, and Plxna4-/- mice. In comparison to WT controls, both Plxna4+/- and Plxna4-/- mice were hyperactive in the open field assay while Plxna4-/- mice displayed a hyper-exploratory (low-anxiety phenotype) in the elevated plus maze. Importantly, both Plxna4+/- and Plxna4-/- mice displayed prominent deficits in learning and memory in the contextual fear-conditioning paradigm. Thus, even a 50% reduction in the level of PLXNA4 is sufficient to cause memory impairments, raising the possibility that memory problems seen in AD patients could be due to reductions in the level of PLXNA4. Both CLU and PLXNA4 have been genetically associated with AD risk and our data thus provide a direct relationship between two AD risk genes. Our data suggest that increasing the levels of PLXNA4 or targeting CLU-PLXNA4 interactions may have therapeutic value in AD.

Fuhrman Grade and Neutrophil-To-Lymphocyte Ratio Influence on Survival in Patients With Metastatic Renal Cell Carcinoma Treated With First-Line Tyrosine Kinase Inhibitors.

BACKGROUND: The present study investigated the various features that might influence the overall survival (OS) of patients with metastatic renal cell carcinoma (RCC) treated with first-line tyrosine kinase inhibitors (TKIs). PATIENTS AND METHODS: A retrospective analysis was performed of consecutive patients with metastatic RCC, in whom treatment with a first-line TKI was initiated from January 2010 to December 2014, at the Department of Oncology, Military Institute of Medicine (Warsaw, Poland). Cox proportional hazards regression was used to construct a prognostic model that included independent factors for OS. We validated the model using 2 bootstrap procedures and calculation of the bias-corrected concordance index. RESULTS: Of the 266 patients included in the study, 201, 45, and 20 received sunitinib, pazopanib, and sorafenib, respectively. The median OS for the whole cohort was 24.8 months (95% confidence interval, 20.2-29.4 months). Six factors were independently associated with poor survival: Eastern Cooperative Oncology Group performance status > 0 (P < .0001), Fuhrman grade 3 to 4 (P < .0001), hemoglobin less than the lower limit of normal (P < .0001), lactate dehydrogenase greater than the upper limit of normal (P = .0011), neutrophil-to-lymphocyte ratio ≥ 4 (P < .0001), and > 2 metastatic sites (P = .0012). The bias-corrected concordance index was 0.751. CONCLUSION: Fuhrman grade and neutrophil-to-lymphocyte ratio are potential factors that affect the survival of patients with metastatic RCC treated with first-line TKIs. The presented prognostic model demonstrated satisfactory performance but requires external validation with a larger data set.

Are primary renal cell carcinoma and metastases of renal cell carcinoma the same cancer?

Metastasis is a process consisting of cells spreading from the primary site of the cancer to distant parts of the body. Our understanding of this spread is limited and molecular mechanisms causing particular characteristics of metastasis are still unknown. There is some evidence that primary renal cell carcinoma (RCC) and metastases of RCC exhibit molecular differences that may effect on the biological characteristics of the tumor. Some authors have detected differences in clear cell and nonclear cell component between these 2 groups of tumors. Investigators have also determined that primary RCC and metastases of RCC diverge in their range of renal-specific markers and other protein expression, gene expression pattern, and microRNA expression. There are also certain proteins that are variously expressed in primary RCCs and their metastases and have effect on clinical outcome, e.g., endothelin receptor type B, phos-S6, and CD44. However, further studies are needed on large cohorts of patients to identify differences representing promising targets for prognostic purposes predicting disease-free survival and the metastatic burden of a patient as well as their suitability as potential therapeutic targets. To sum up, in this review we have attempted to summarize studies connected with differences between primary RCC and its metastases and their influence on the biological characteristics of renal cancer.

Mutation of the PIK3CA gene as a prognostic factor in patients with colorectal cancer.

Colorectal cancer (CRC) is one of the most common cancers worldwide, with ~700,000 mortalities occurring due to CRC in 2012. The treatment options are effective in a small percentage of patients, and it is important to identify specific biomarkers in order to determine patients for whom the available therapies will be beneficial. It has been hypothesised that the PIK3CA gene mutation may affect the response to therapy of patients with metastatic CRC. In the present study, primary tumour specimens were collected from 156 patients with CRC who were treated in the Military Institute of Medicine in Warsaw (Warsaw, Poland). Codons 12 and 13 of exon 1 of KRAS, exons 11 and 15 of BRAF and exons 9 and 20 of PIK3CA were analysed for mutation using direct sequencing. The prognostic value of each mutation and the clinical and pathological variables of these tumours were estimated. The results revealed that PIK3CA mutations were present in 15 patients (9.6%), of whom seven (46.7%) possessed mutations in codon 9 and eight (53.3%) possessed mutations in codon 20. Mutation in the PIK3CA gene was detected in six patients with KRAS gene mutations, which accounted for 40% of PIK3CA-mutated tumours, and in one patient with BRAF mutations, which accounted for 6.6% of PIK3CA-mutated tumours. No significant differences were identified between the overall survival (OS) rates of patients with PIK3CA mutations (median OS, 56.7 months) and those with wild-type PIK3CA genes (median OS, 47.6 months) (P=0.1270). Univariate analysis identified that the following prognostic factors affected the OS rate in the current patient cohort: Gender, female patients survived for 57.5 months compared with 39.3 months for male patients (P=0.0111); and lymph node involvement grade, as survival of patients without lymph node metastases was 61.4 months compared with 45.4 months in patients presenting with metastases (P=0.0122). The findings of the present analysis indicate that PIK3CA mutation status is not a prognostic factor in CRC patients. In addition, no statistically significant association exists between tumours with PIK3CA mutations and clinical or pathological factors.

A novel tau mutation, p.K317N, causes globular glial tauopathy.

Globular glial tauopathies (GGTs) are 4-repeat tauopathies neuropathologically characterized by tau-positive, globular glial inclusions, including both globular oligodendroglial inclusions and globular astrocytic inclusions. No mutations have been found in 25 of the 30 GGT cases reported in the literature who have been screened for mutations in microtubule associated protein tau (MAPT). In this report, six patients with GGT (four with subtype III and two with subtype I) were screened for MAPT mutations. They included 4 men and 2 women with a mean age at death of 73 years (55-83 years) and mean age at symptomatic onset of 66 years (50-77 years). Disease duration ranged from 5 to 14 years. All were homozygous for the MAPT H1 haplotype. Three patients had a positive family history of dementia, and a novel MAPT mutation (c.951G>C, p.K317N) was identified in one of them, a patient with subtype III. Recombinant tau protein bearing the lysine-to-asparagine substitution at amino acid residue 317 was used to assess functional significance of the variant on microtubule assembly and tau filament formation. Recombinant p.K317N tau had reduced ability to promote tubulin polymerization. Recombinant 3R and 4R tau bearing the p.K317N mutation showed decreased 3R tau and increased 4R tau filament assembly. These results strongly suggest that the p.K317N variant is pathogenic. Sequencing of MAPT should be considered in patients with GGT and a family history of dementia or movement disorder. Since several individuals in our series had a positive family history but no MAPT mutation, genetic factors other than MAPT may play a role in disease pathogenesis.