L-Arginine/NO Pathway Metabolites in Colorectal Cancer: Relevance as Disease Biomarkers and Predictors of Adverse Clinical Outcomes Following Surgery

Hypoxia-induced NOS1 as a therapeutic target in hypercholesterolemia-related colorectal cancer

BACKGROUND

It is well established that hypercholesterolemia increases the risk of atherosclerosis, especially because it reduces the availability of nitric oxide (NO). However, the relationship between hypercholesterolemia and NO in regulating colorectal cancer development and progression remains unknown.

METHODS

We conducted bioinformatics analysis, qRT-PCR, ChIP-qPCR assays, luciferase report assays, clonogenic survival assays, and multiple mouse models to investigate the function and mechanism of hypercholesterolemia in regulating NO signaling. Additionally, NOS inhibitors were used to evaluate the potential of therapeutic strategy in anti-tumor response.

RESULTS

Here, we show that oxidized low-density lipoprotein (oxLDL) cholesterol and its receptor LOX-1 are essential for hypercholesterolemia-induced colorectal tumorigenesis. Mechanically, the oxLDL promotes the oxidant stress-dependent induction of hypoxia signaling to transcriptionally up-regulate NO synthase (NOS) especially NOS1 expression in colorectal cancer (CRC) cells. More importantly, our results suggested that selective inhibition of NOS1 with its specific inhibitor Nω-Propyl-L-arginine is a suitable therapeutic strategy for hypercholesterolemia-related CRC with both efficacy and toxicity reduction.

CONCLUSIONS

Our findings established that hypercholesterolemia induces the oxidant stress-dependent induction of hypoxia signaling to transcriptionally up-regulate NOS1 expression in CRC cells, and the clinically applicable NOS1 inhibitor Nω-Propyl-L-arginine represents an effective therapeutic strategy for hypercholesterolemia-related CRC.

Circulating metabolic markers after surgery identify patients at risk for severe postoperative complications: a prospective cohort study in colorectal cancer

BACKGROUND

Early detection of postoperative complications after colorectal cancer (CRC) surgery is associated with improved outcomes. The aim was to investigate early metabolomics signatures capable to detect patients at risk for severe postoperative complications after CRC surgery.

MATERIALS AND METHODS

Prospective cohort study of patients undergoing CRC surgery from 2015 to 2018. Plasma samples were collected before and after surgery, and analyzed by mass spectrometry obtaining 188 metabolites and 21 ratios. Postoperative complications were registered with Clavien-Dindo Classification and Comprehensive Complication Index.

RESULTS

One hundred forty-six patients were included. Surgery substantially modified metabolome and metabolic changes after surgery were quantitatively associated with the severity of postoperative complications. The strongest positive relationship with both Clavien-Dindo and Comprehensive Complication Index (β=4.09 and 63.05, P <0.001) corresponded to kynurenine/tryptophan, against an inverse relationship with lysophosphatidylcholines (LPCs) and phosphatidylcholines (PCs). Patients with LPC18:2/PCa36:2 below the cut-off 0.084 µM/µM resulted in a sevenfold higher risk of major complications (OR=7.38, 95% CI: 2.82-21.25, P <0.001), while kynurenine/tryptophan above 0.067 µM/µM a ninefold (OR=9.35, 95% CI: 3.03-32.66, P <0.001). Hexadecanoylcarnitine below 0.093 µM displayed a 12-fold higher risk of anastomotic leakage-related complications (OR=11.99, 95% CI: 2.62-80.79, P =0.004).

CONCLUSION

Surgery-induced phospholipids and amino acid dysregulation is associated with the severity of postoperative complications after CRC surgery, including anastomotic leakage-related outcomes. The authors provide quantitative insight on metabolic markers, measuring vulnerability to postoperative morbidity that might help guide early decision-making and improve surgical outcomes.

Epigenetic and metabolic reprogramming in inflammatory bowel diseases: diagnostic and prognostic biomarkers in colorectal cancer

BACKGROUND AND AIM

"Inflammatory bowel disease" (IBD) is a chronic, relapsing inflammatory disease of the intestinal tract that typically begins at a young age and might transit to colorectal cancer (CRC). In this manuscript, we discussed the epigenetic and metabolic change to present a extensive view of IBDs transition to CRC. This study discusses the possible biomarkers for evaluating the condition of IBDs patients, especially before the transition to CRC.

RESEARCH APPROACH

We searched "PubMed" and "Google Scholar" using the keywords from 2000 to 2022.

DISCUSSION

In this manuscript, interesting titles associated with IBD and CRC are discussed to present a broad view regarding the epigenetic and metabolic reprogramming and the biomarkers.

CONCLUSION

Epigenetics can be the main reason in IBD transition to CRC, and Hypermethylation of several genes, such as VIM, OSM4, SEPT9, GATA4 and GATA5, NDRG4, BMP3, ITGA4 and plus hypomethylation of LINE1 can be used in IBD and CRC management. Epigenetic, metabolisms and microbiome-derived biomarkers, such as Linoleic acid and 12 hydroxy 8,10-octadecadienoic acid, Serum M2-pyruvate kinase and Six metabolic genes (NAT2, XDH, GPX3, AKR1C4, SPHK and ADCY5) expression are valuable biomarkers for early detection and transition to CRC condition. Some miRs, such as miR-31, miR-139-5p, miR -155, miR-17, miR-223, miR-370-3p, miR-31, miR -106a, miR -135b and miR-320 can be used as biomarkers to estimate IBD transition to CRC condition.

The association between symmetric dimethylarginine concentrations and various neoplasms in dogs and cats

Following the introduction of the symmetric dimethylarginine (SDMA) immunoassay, cases were reported where the SDMA concentration was markedly increased above the reference interval (RI) with neither concurrent increases in serum creatinine (Cr) concentrations nor clinical signs of kidney disease. Many of these animals were also concurrently diagnosed with cancer, most commonly lymphoma. The purpose of the study was to evaluate the association of increased SDMA in dogs and cats with lymphoma and other cancers as compared with age- and breed-matched non-tumour controls. In this retrospective case-control study, serum chemistry results from 1804 tumour cases, and age- and breed-matched non-tumour control animals were used. Matched-pair odds ratios between animals diagnosed with neoplasms and non-tumour controls for dichotomized SDMA values were determined by tumour type. SDMA concentrations were significantly higher in dogs and cats with lymphoma (p < .0001) compared with non-tumour controls. The odds ratio for increased SDMA concentrations in dogs with lymphoma was 10.0 (95% CI, 5.98-16.72) and for cats with lymphoma was 3.04 (95% CI 1.95-4.73). A significant number of canine and feline lymphoma cases had an increased SDMA concentration not associated with an increased Cr concentration (p < .001). Canine and feline lymphoma patients have an increased odds of having a SDMA concentration above the RI at diagnosis. Further characterization and evaluation of dogs and cats with lymphoma is required to help understand the mechanism(s) and the clinical significance of these alterations.

Asparagine Metabolism in Tumors Is Linked to Poor Survival in Females with Colorectal Cancer: A Cohort Study

The interplay between the sex-specific differences in tumor metabolome and colorectal cancer (CRC) prognosis has never been studied and represents an opportunity to improve patient outcomes. This study examines the link between tumor metabolome and prognosis by sex for CRC patients. Using untargeted metabolomics analysis, abundances of 91 metabolites were obtained from primary tumor tissues from 197 patients (N = 95 females, N = 102 males) after surgical colectomy for stage I-III CRC. Cox Proportional hazard (PH) regression models estimated the associations between tumor metabolome and 5-year overall survival (OS) and recurrence-free survival (RFS), and their interactions with sex. Eleven metabolites had significant sex differences in their associations with 5-year OS, and five metabolites for 5-year RFS. The metabolites asparagine and serine had sex interactions for both OS and RFS. Furthermore, in the asparagine synthetase (ASNS)-catalyzed asparagine synthesis pathway, asparagine was associated with substantially poorer OS (HR (95% CI): 6.39 (1.78–22.91)) and RFS (HR (95% CI): 4.36 (1.39–13.68)) for female patients only. Similar prognostic disadvantages in females were seen in lysophospholipid and polyamine synthesis. Unique metabolite profiles indicated that increased asparagine synthesis was associated with poorer prognosis for females only, providing insight into precision medicine for CRC treatment stratified by sex.

Amperometric Biosensors for L-Arginine Determination Based on L-Arginine Oxidase and Peroxidase-Like Nanozymes

There are limited data on amperometric biosensors (ABSs) for L-arginine (Arg) determination based on oxidases that produce hydrogen peroxide (H2O2) as a byproduct of enzymatic reaction, and artificial peroxidases (POs) for decomposition of H2O2. The most frequently proposed Arg-sensitive oxidase-based ABSs contain at least two enzymes in the bioselective layer; this complicates the procedure and increases the cost of analysis. Therefore, the construction of a one-enzyme ABS for Arg analysis is a practical problem. In the current work, fabrication, and characterization of three ABS types for the direct measurement of Arg were proposed. L-arginine oxidase (ArgO) isolated from the mushroom Amanita phalloides was co-immobilized with PO-like nanozymes (NZs) on the surface of graphite electrodes. As PO mimetics, chemically synthesized NZs of CeCu (nCeCU) and NiPtPd (nNiPtPd), as well as green-synthesized hexacyanoferrate of copper (gCuHCF), were used. The novel ABSs exhibited high sensitivity and selectivity to Arg, broad linear ranges and good storage stabilities. Two ABSs were tested on real samples of products containing Arg, including the pharmaceutical preparation “Tivortine”, juices, and wine. A high correlation (R = 0.995) was demonstrated between the results of testing “Tivortine” and juice using nCeCU/GE and nNiPtPd/GE. It is worth mentioning that only a slight difference (less than 1%) was observed for “Tivortin” between the experimentally determined content of Arg and its value declared by the producer. The proposed ArgO-NZ-based ABSs may be promising for Arg analysis in different branches of science, medicine, and industry.

Altered L-Arginine Metabolic Pathways in Gastric Cancer: Potential Therapeutic Targets and Biomarkers

There is a pressing need for molecular targets and biomarkers in gastric cancer (GC). We aimed at identifying aberrations in L-arginine metabolism with therapeutic and diagnostic potential. Systemic metabolites were quantified using mass spectrometry in 293 individuals and enzymes’ gene expression was quantified in 29 paired tumor-normal samples using qPCR and referred to cancer pathology and molecular landscape. Patients with cancer or benign disorders had reduced systemic arginine, citrulline, and ornithine and elevated symmetric dimethylarginine and dimethylamine. Citrulline and ornithine depletion was accentuated in metastasizing cancers. Metabolite diagnostic panel had 91% accuracy in detecting cancer and 70% accuracy in differentiating cancer from benign disorders. Gastric tumors had upregulated NOS2 and downregulated ASL, PRMT2, ORNT1, and DDAH1 expression. NOS2 upregulation was less and ASL downregulation was more pronounced in metastatic cancers. Tumor ASL and PRMT2 expression was inversely related to local advancement. Enzyme up- or downregulation was greater or significant solely in cardia subtype. Metabolic reprogramming in GC includes aberrant L-arginine metabolism, reflecting GC subtype and pathology, and is manifested by altered interplay of its intermediates and enzymes. Exploiting L-arginine metabolic pathways for diagnostic and therapeutic purposes is warranted. Functional studies on ASL, PRMT2, and ORNT1 in GC are needed.

Sex, Type of Surgery, and Surgical Site Infections Are Associated with Perioperative Cortisol in Colorectal Cancer Patients

Excessive endocrine response to trauma negatively affects patients’ well-being. Cortisol dynamics following robot-assisted colorectal surgery are unknown. We aimed at determining the impact of cancer pathology and surgery-related factors on baseline cortisol levels and analyzed its time-profile in colorectal cancer patients undergoing open or robot-assisted surgery. Cortisol levels were measured using liquid chromatography quadrupole time-of-flight mass spectrometry. Baseline cortisol was not associated with any patient- or disease-related factors. Post-surgery cortisol increased by 36% at 8 h and returned to baseline on postoperative day three. The cortisol time profile was significantly affected by surgery type, estimated blood loss, and length of surgery. Baseline-adjusted cortisol increase was greater in females at hour 8 and in both females and patients from open surgery group at hour 24. Solely in the open surgery group, cortisol dynamics paralleled changes in interleukin (IL)-1β, IL-10, IL-1ra, IL-7, IL-8 and tumor necrosis factor (TNF)-α but did not correlate with changes in IL-6 or interferon (IFN)-γ at any time-point. Cortisol co-examined with C-reactive protein was predictive of surgical site infections (SSI) with high accuracy. In conclusion, patient’s sex and surgery invasiveness affect cortisol dynamics. Surgery-induced elevation can be reduced by minimally invasive robot-assisted procedures. Cortisol and C-reactive protein as SSI biomarkers might be of value in the evaluation of safety of early discharge of patients.

Simultaneous LC-MS/MS-Based Quantification of Free 3-Nitro-l-tyrosine, 3-Chloro-l-tyrosine, and 3-Bromo-l-tyrosine in Plasma of Colorectal Cancer Patients during Early Postoperative Period

Quantification with satisfactory specificity and sensitivity of free 3-Nitro-l-tyrosine (3-NT), 3-Chloro-l-tyrosine (3-CT), and 3-Bromo-l-tyrosine (3-BT) in biological samples as potential inflammation, oxidative stress, and cancer biomarkers is analytically challenging. We aimed at developing a liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based method for their simultaneous analysis without an extract purification step by solid-phase extraction. Validation of the developed method yielded the following limits of detection (LOD) and quantification (LOQ) for 3-NT, 3-BT, and 3-CT: 0.030, 0.026, 0.030 ng/mL (LODs) and 0.100, 0.096, 0.098 ng/mL (LOQs). Coefficients of variation for all metabolites and tested concentrations were <10% and accuracy was within 95-105%. Method applicability was tested on colorectal cancer patients during the perioperative period. All metabolites were significantly higher in cancer patients than healthy controls. The 3-NT was significantly lower in advanced cancer and 3-BT showed a similar tendency. Dynamics of 3-BT in the early postoperative period were affected by type of surgery and presence of surgical site infections. In conclusion, a sensitive and specific LC-MS/MS method for simultaneous quantification of free 3-NT, 3-BT, and 3-CT in human plasma has been developed.

L-Arginine/Nitric Oxide Pathway Is Altered in Colorectal Cancer and Can Be Modulated by Novel Derivatives from Oxicam Class of Non-Steroidal Anti-Inflammatory Drugs

L-arginine/nitric oxide pathway metabolites are altered in colorectal cancer (CRC). We evaluated underlying changes in pathway enzymes in 55 paired tumor/tumor-adjacent samples and 20 normal mucosa using quantitative-PCR and assessed the impact of classic and novel oxicam analogues on enzyme expression and intracellular metabolite concentration (LC-MS/MS) in Caco-2, HCT116, and HT-29 cells. Compared to normal mucosa, ARG1, PRMT1, and PRMT5 were overexpressed in both tumor and tumor-adjacent tissue and DDAH2 solely in tumor-adjacent tissue. Tumor-adjacent tissue had higher expression of ARG1, DDAH1, and DDAH2 and lower NOS2 than patients-matched tumors. The ARG1 expression in tumors increased along with tumor grade and reflected lymph node involvement. Novel oxicam analogues with arylpiperazine moiety at the thiazine ring were more effective in downregulating DDAHs and PRMTs and upregulating ARG2 than piroxicam and meloxicam. An analogue distinguished by propylene linker between thiazine's and piperazine's nitrogen atoms and containing two fluorine substituents was the strongest inhibitor of DDAHs and PRMTs expression, while an analogue containing propylene linker but no fluorine substituents was the strongest inhibitor of ARG2 expression. Metabolic reprogramming in CRC includes overexpression of DDAHs and PRMTs in addition to ARG1 and NOS2 and is not restricted to tumor tissue but can be modulated by novel oxicam analogues.

Esophageal Squamous Cell Carcinoma Is Accompanied by Local and Systemic Changes in L-arginine/NO Pathway

The L-arginine/NO pathway holds promise as a source of potential therapy target and biomarker; yet, its status and utility in esophageal squamous cell carcinoma (ESCC) is unclear. We aimed at quantifying pathway metabolites in sera from patients with ESCC (n = 61) and benign conditions (n = 62) using LC-QTOF-MS and enzyme expression in esophageal tumors and matched noncancerous samples (n = 40) using real-time PCR with reference to ESCC pathology and circulating immune/inflammatory mediators, quantified using Luminex xMAP technology. ESCC was associated with elevated systemic arginine and asymmetric dimethylarginine. Citrulline decreased and arginine bioavailability increased along with increasing ESCC advancement. Compared to adjacent tissue, tumors overexpressed ODC1, NOS2, PRMT1, and PRMT5 but had downregulated ARG1, ARG2, and DDAH1. Except for markedly higher NOS2 and lower ODC1 in tumors from M1 patients, the pathology-associated changes in enzyme expression were subtle and present also in noncancerous tissue. Both the local enzyme expression level and systemic metabolite concentration were related to circulating inflammatory and immune mediators, particularly those associated with eosinophils and those promoting viability and self-renewal of cancer stem cells. Metabolic reprogramming in ESCC manifests itself by the altered L-arginine/NO pathway. Upregulation of PRMTs in addition to NOS2 and ODC1 and the pathway link with stemness-promoting cytokines warrants further investigation.