Loss of NOS1 expression in high-grade renal cell carcinoma associated with a shift of NO signalling

Disturbances in Nitric Oxide Cycle and Related Molecular Pathways in Clear Cell Renal Cell Carcinoma

It is important to note that maintaining adequate levels of nitric oxide (NO), the turnover, and the oxidation level of nitrogen are essential for the optimal progression of cellular processes, and alterations in the NO cycle indicate a crucial step in the onset and progression of multiple diseases. Cellular accumulation of NO and reactive nitrogen species in many types of tumour cells is expressed by an increased susceptibility to oxidative stress in the tumour microenvironment. Clear cell renal cell carcinoma (ccRCC) is a progressive metabolic disease in which tumour cells can adapt to metabolic reprogramming to enhance NO production in the tumour space. Understanding the factors governing NO biosynthesis metabolites in ccRCC represents a relevant, valuable approach to studying NO-based anticancer therapy. Exploring the molecular processes mediated by NO, related disturbances in molecular pathways, and NO-mediated signalling pathways in ccRCC could have significant therapeutic implications in managing and treating this condition.

Serum Oxidative and Nitrosative Stress Markers in Clear Cell Renal Cell Carcinoma

Oxidative stress is believed to be a factor in the development and progression of renal cell carcinoma (RCC). The identification of the oxidative and nitrosative modification of proteins and the definition of their roles in clear cell RCC (ccRCC) may be helpful in the elaboration of targeted therapeutic approaches to mitigate protein damage. This study aimed to investigate the status of oxidative/nitrosative stress and to explore its role in the development and progression. The studied group consisted of 48 newly diagnosed ccRCC and 30 healthy controls. Serum levels of oxidative stress markers-advanced oxidation protein products (AOPP), thiol groups, Amadori reaction products, 3-nitrotyrosine, nitrate/nitrite, malondialdehyde (MDA), 4-hydroxy-2-nonenal and total antioxidant capacity (TAC)-were determined. Additionally, associations between tumour stage assessed according to TNM classification, histological grade, and the effect of the presence of angioinvasion on the level of stress markers were evaluated. The levels of Amadori products, 3-nitrotyrosine, and nitrate/nitrite were elevated, while the levels of thiol groups and TAC decreased in the ccRCC group. The levels of AOPP, Amadori, and 3-nitrotyrosine increased, and thiol groups and TAC levels decreased with the increasing pathological stage of the tumour. In the case of advanced histological assessment of the tumour, we found decreasing levels of thiol groups and increasing levels of MDA. In patients with angioinvasion, nitrate/nitrite and MDA levels were significantly elevated compared to those in patients without angioinvasion. Oxidative stress increased with the progression of the disease assessed according to the TNM and histological grade. These results demonstrate systemic oxidative stress in ccRCC, suggesting the therapeutic application of antioxidants.

A network medicine approach for identifying diagnostic and prognostic biomarkers and exploring drug repurposing in human cancer

Cancer is a heterogeneous disease mainly driven by abnormal gene perturbations in regulatory networks. Therefore, it is appealing to identify the common and specific perturbed genes from multiple cancer networks. We developed an integrative network medicine approach to identify novel biomarkers and investigate drug repurposing across cancer types. We used a network-based method to prioritize genes in cancer-specific networks reconstructed using human transcriptome and interactome data. The prioritized genes show extensive perturbation and strong regulatory interaction with other highly perturbed genes, suggesting their vital contribution to tumorigenesis and tumor progression, and are therefore regarded as cancer genes. The cancer genes detected show remarkable performances in discriminating tumors from normal tissues and predicting survival times of cancer patients. Finally, we developed a network proximity approach to systematically screen drugs and identified dozens of candidates with repurposable potential in several cancer types. Taken together, we demonstrated the power of the network medicine approach to identify novel biomarkers and repurposable drugs in multiple cancer types. We have also made the data and code freely accessible to ensure reproducibility and reusability of the developed computational workflow.

An eleven metabolic gene signature-based prognostic model for clear cell renal cell carcinoma

In this study, we performed bioinformatics and statistical analyses to investigate the prognostic significance of metabolic genes in clear cell renal cell carcinoma (ccRCC) using the transcriptome data of 539 ccRCC and 72 normal renal tissues from TCGA database. We identified 79 upregulated and 45 downregulated (n=124) metabolic genes in ccRCC tissues. Eleven prognostic metabolic genes (NOS1, ALAD, ALDH3B2, ACADM, ITPKA, IMPDH1, SCD5, FADS2, ACHE, CA4, and HK3) were identified by further analysis. We then constructed an 11-metabolic gene signature-based prognostic risk score model and classified ccRCC patients into high- and low-risk groups. Overall survival (OS) among the high-risk ccRCC patients was significantly shorter than among the low-risk ccRCC patients. Receiver operating characteristic (ROC) curve analysis of the prognostic risk score model showed that the areas under the ROC curve for the 1-, 3-, and 5-year OS were 0.810, 0.738, and 0.771, respectively. Thus, our prognostic model showed favorable predictive power in the TCGA and E-MTAB-1980 ccRCC patient cohorts. We also established a nomogram based on these eleven metabolic genes and validated internally in the TCGA cohort, showing an accurate prediction for prognosis in ccRCC.

Polymorphism of Nitric Oxide Synthase 1 Affects the Clinical Phenotypes of Ischemic Stroke in Korean Population

Objective

To investigate whether four single nucleotide polymorphisms (SNPs) rs2293054 [Ile734Ile], rs1047735 [His902His], rs2293044 [Val1353Val], rs2682826 (3'UTR) of nitric oxide synthase 1 (NOS1) are associated with the development and clinical phenotypes of ischemic stroke.

Methods

We enrolled 120 ischemic stroke patients and 314 control subjects. Ischemic stroke patients were divided into subgroups according to the scores of the National Institutes of Health Stroke Survey (NIHSS, <6 and ≥6) and Modified Barthel Index (MBI, <60 and ≥60). SNPStats, SNPAnalyzer, and HelixTree programs were used to calculate odds ratios (ORs), 95% confidence intervals (CIs), and p-values. Multiple logistic regression models were performed to analyze genetic data.

Results

No SNPs of the NOS1 gene were found to be associated with ischemic stroke. However, in an analysis of clinical phenotypes, we found that rs2293054 was associated with the NIHSS scores of ischemic stroke patients in codominant (p=0.019), dominant (p=0.007), overdominant (p=0.033), and log-additive (p=0.0048) models. Also, rs2682826 revealed a significant association in the recessive model (p=0.034). In allele frequency analysis, we also found that the T alleles of rs2293054 were associated with lower NIHSS scores (p=0.007). Respectively, rs2293054 had a significant association in the MBI scores of ischemic stroke in codominant (p=0.038), dominant (p=0.031), overdominant (p=0.045), and log-additive (p=0.04) models.

Conclusion

These results suggest that NOS1 may be related to the clinical phenotypes of ischemic stroke in Korean population.

Effect of a functional polymorphism in the pre-miR-146a gene on the risk and prognosis of renal cell carcinoma

MicroRNAs (miRNAs) are non-coding RNAs that function as regulators of tumor suppressors and oncogenes. A G>C polymorphism (rs2910164) in the miR‑146a precursor sequence leads to a functional change associated with a risk for various types of malignancy. The role of this single nucleotide polymorphism in the pathogenesis of renal cell carcinoma (RCC) has not yet been examined. The present study evaluated the association between rs2910164 genotypes and the risk and prognosis of RCC in a population comprised of 421 RCC cases and 432 controls. Unconditional logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (CI) for rs2910164 genotypes according to case status. Cox proportional hazards regression modeling was used to estimate hazards ratios and 95% CIs according to the genotypes among the RCC patients. It was found that the rs2910164 GG and GC genotypes were associated with an increased risk of RCC only in senior subjects (>57‑years old; adjusted OR=1.59, 95% CI=1.04‑2.43). Furthermore, the GC and GG genotypes were associated with a poorer survival rate among patients with RCC compared with the CC genotype (P=0.002). In conclusion, the observed association between the GG and GC genotype and poorer survival rate of RCC was at least partially mediated by the decreased expression of miR-146a.

The impact of immunohistochemical expression of nitric oxide synthases on clinical and pathological features of renal cell carcinoma

PURPOSE

To evaluate the immunohistochemical expression of nitric oxide synthase (NOS) types 1, 2, and 3 in intratumoral and non-neoplastic samples of renal cell carcinoma (RCC) and correlate it with the clinical and pathological features of this malignancy.

METHODS

We analyzed 110 patients with RCC underwent radical nephrectomy (RN) or partial nephrectomy (PN) by streptavidin-biotin peroxidase method, tissue microarray, and digital microscopy. As endpoints, NOS expression was correlated with pathological features, overall survival (OS), and cancer-specific survival (CSS).

RESULTS

Non-neoplastic samples had higher NOS3 and lower NOS 2 levels than RCC tissues. Greater expression of all NOS isoforms was associated with larger tumors. High NOS1 expression correlated with microscopic venous invasion (MVI) (p = 0.046) and lymph node metastases (p = 0.007). High NOS2 expression was linked to MVI, more RN performed, and male gender (p = 0.035, p = 0.003, and p = 0.027, respectively). High NOS3 expression correlated with lymph node metastases (p = 0.039), microlymphatic invasion (p = 0.029), invasion of the renal pelvis and ureter (p = 0.004), RN (p = 0.003), and shorter OS (58.1 vs. 79.4 % respectively, p = 0.033) by univariate analysis. DFS was not influenced by any NOS isoform. By multivariate analysis, the risk factors for death were TNM stages III and IV (hazard ratio [HR] = 4.5), high Fuhrman's grade (HR = 2.9), Karnofsky performance status ≤80 (HR = 2.5), progression (HR = 5.5), and recurrence (HR = 6.3). Stage III disease was an independent risk factor for recurrence (HR = 9.5).

CONCLUSIONS

High NOS expression in RCC is associated with a poor prognosis and larger tumors. NOS3 influences OS by univariate analysis.

Post-translational modifications induced by nitric oxide (NO): implication in cancer cells apoptosis

Post-translational modifications of proteins can regulate the balance between survival and cell death signals. It is increasingly recognized that nitric oxide (NO) and reactive oxygen species (ROS)-induced post-translational modifications could play a role in cell death. This review provides an introduction of current knowledge of NO proteins modifications promoting or inhibiting cell death with special attention in cancer cells.

Human colonic myocytes are involved in postischemic inflammation through ADAM17-dependent TNFalpha production

The aim of this study was to identify human colonic resident cells able to initiate an inflammatory response in postischemic injury. Postischemic colonic injury, a condition relevant to various clinical settings, involves an inflammatory cascade in intestinal tissues through the recruitment of circulating inflammatory cells. However, there is no information on the nature of resident cells of the different intestinal layers able to initiate a postischemic inflammatory response. It is however an important issue in the context of a pharmacological approach of the early phase of intestinal ischemia. We reasoned that maintaining the different colonic layers as explant cultures in an oxygenated medium immediately after colonic resection, that is, after an ischemic period, would allow one to identify the resident cells able to initiate an inflammatory cascade, without interference of recruited inflammatory/immune cells. To this end, we designed an explant culture system that operationally defines three compartments in surgical specimens of the human colon, based on the microdissected layers, that is, mucosa, submucosa (containing muscularis mucosae) and muscularis propria. To validate the results obtained in explant cultures in the clinical setting of ischemic colitis, eight cases of sigmoid volvulus were examined. Only the myocytes-containing explants produced tumor necrosis factor alpha (TNFalpha), via an ADAM17 (a disintegrin and metalloproteinase-17)-dependent pathway, as shown by the abrogation of TNFalpha production by the inhibitor Tapi-2. Immunofluorescence studies identified nonvascular and vascular myocytes as resident cells coexpressing TNFalpha and ADAM17, both in our postischemic explant system and in surgical specimens from ischemic colitis patients. Finally, time-course experiments on explanted tissues showed that TNFalpha production by myocytes was an early event triggered by a postischemic oxidative stress involving nuclear factor kappa B (NF-kappaB). In conclusion, this study identifies human intestinal myocytes as resident cells able to initiate an inflammatory reaction through TNFalpha production in postischemic conditions, and delineates two points of control in TNFalpha production, NF-kappaB and ADAM17, which can be targeted by pharmacological manipulation.