Free fatty acid analysis in ascitic fluid improves diagnosis in malignant abdominal tumors

Polyunsaturated fatty acids promote M2-like TAM deposition via dampening RhoA-YAP1 signaling in the ovarian cancer microenvironment

BACKGROUND

Peritoneal metastases frequently occur in epithelial ovarian cancer (EOC), resulting in poor prognosis and survival rates. Tumor-associated-macrophages (TAMs) massively infiltrate into ascites spheroids and are multi-polarized as protumoral M2-like phenotype, orchestrating the immunosuppression and promoting tumor progression. However, the impact of omental conditioned medium/ascites (OCM/AS) on TAM polarization and its function in tumor progression remains elusive.

METHODS

The distribution and polarization of TAMs in primary and omental metastatic EOC patients' tumors and ascites were examined by m-IHC, FACS analysis, and immunofluorescence. QPCR, immunofluorescence, FACS analysis, lipid staining assay, ROS assay, and Seahorse real-time cell metabolic assay characterized TAMs as being polarized in the ascites microenvironment. The oncogenic role of TAMs in tumor cells was demonstrated by co-cultured migration/invasion, proliferation, and spheroid formation assays. Mechanistic studies of the regulations of TAM polarization were performed by using RNA-Seq, GTPase pull-down, G-LISA activation assays, and other biochemical assays. A Yap1 macrophages (MФs) conditional knockout (cKO) mouse model demonstrated the roles of YAP1 in TAM polarization status and its pro-metastatic function. Finally, the anti-metastatic potential of targeting TAMs through restoring YAP1 by pharmacological agonist XMU MP1 was demonstrated in vitro and in vivo.

RESULTS

Abundant polyunsaturated fatty acids (PUFAs) in OCM/AS suppressed RhoA-GTPase activities, which, in turn, downregulated nuclear YAP1 in MФs, leading to increased protumoral TAM polarization accompanied by elevated OXPHOS metabolism. Abolishment of YAP1 in MФs further confirmed that a higher M2/M1 ratio of TAM polarization could alleviate CD8+ T cell infiltration and cytotoxicity in vivo. Consistently, the loss of YAP1 has been observed in EOC metastatic tissues, suggesting its clinical relevance. On the contrary, restoration of YAP1 expression by pharmaceutical inhibition of MST1/2 induced conversion of M2-to-M1-like polarized MФs, elevating the infiltration of CD8+ T cells and attenuating tumor growth.

CONCLUSION

This study revealed that PUFAs-enriched OCM/AS of EOC promotes M2-like TAM polarization through RhoA-YAP1 inhibition, where YAP1 downregulation is required for accelerating protumoral M2-like TAM polarization, thereby causing immunosuppression and enhancing tumor progression. Conversion of M2-to-M1-like polarized MФs through Yap1 activation inhibits tumor progression and contributes to developing potential TAMs-targeted immunotherapies in combating EOC peritoneal metastases.

Tumor microenvironment in ovarian cancer peritoneal metastasis

Ovarian cancer (OC) is one of the most common gynecological malignancies with high morbidity and mortality. The peritoneum is one of the most common metastatic sites in ovarian cancer, involving large amounts of ascites. However, its mechanism is unclear. The peritoneal microenvironment composed of peritoneal effusion and peritoneum creates favorable conditions for ovarian cancer progression and metastasis. Here, we reviewed the peritoneal metastasis patterns and molecular mechanisms of ovarian cancer, as well as major components of the peritoneal microenvironment, peritoneal effusion, and immune microenvironment, and investigated the relationship between the peritoneal microenvironment and ovarian cancer metastasis.

A Metabolomic Analysis of Cirrhotic Ascites

Ascites is a common complication of decompensated liver cirrhosis, and yet relatively little is known about its biochemical composition. We conducted two metabolomic investigations, comparing the profile of ascites from 33 cirrhotic patients and postoperative peritoneal drainage fluid from 33 surgical patients (Experiment 1). The profile of paired ascites and plasma was also compared in 17 cirrhotic patients (Experiment 2). Gas chromatography−mass spectrometry-based metabolomics identified 29 metabolites that significantly characterized ascites fluid, whether postoperative drainage fluid or plasma were used as controls. Ten elevated amino acids (glutamine, proline, histidine, tyrosine, glycine, valine, threonine, methionine, lysine, phenylalanine) and seven diminished lipids (laurate, myristate, palmitate, oleate, vaccenate, stearate, cholesterol) largely comprised the cirrhotic ascites metabolomic phenotype that differed significantly (adjusted p < 0.002 to 0.03) from peritoneal drainage fluid or plasma. The pattern of upregulated amino acids in cirrhotic ascites did not indicate albumin proteolysis by peritoneal bacteria. Bidirectional clustering showed that the more severe the cirrhosis, the lower the lipid concentration in ascitic fluid. The metabolomic compartment of ascites in patients with decompensated cirrhosis is characterized by increased amino acids and decreased lipids. These novel findings have potential relevance for diagnostic purposes.

Linoleic and oleic acids enhance cell migration by altering the dynamics of microtubules and the remodeling of the actin cytoskeleton at the leading edge

Fatty acids (FA) have a multitude of biological actions on living cells. A target of their action is cell motility, a process of critical importance during cancer cell dissemination. Here, we studied the effect of unsaturated FA on ovarian cancer cell migration in vitro and its role in regulating cytoskeleton structures that are essential for cell motility. Scratch wound assays on human ovary cancer SKOV-3 cell monolayers revealed that low doses (16 μM) of linoleic acid (LA, 18:2 ω6) and oleic acid (OA; 18:1 ω9) promoted migration, while α-linolenic acid (ALA, 18:3 ω3), showed a migration rate similar to that of the control group. Single cell tracking demonstrated that LA and OA-treated cells migrated faster and were more orientated towards the wound closure than control. In vitro addition of those FA resulted in an increased number, length and protrusion speed of filopodia and also in a prominent and dynamic lamellipodia at the cell leading edge. Using time-lapse video-microscopy and FRAP we observed an increase in both the speed and frequency of actin waves associated with more mobile actin and augmented Rac1 activity. We also observed that FA induced microtubule-organizing center (MTOC)-orientation towards the cell front and affected the dynamics of microtubules (MT) in the direction of cell migration. We propose that environmental cues such as OA and LA present in ascitic fluid, should be taken into account as key factors for the regulation of cell migration.

Targeting the tumour microenvironment in platinum-resistant ovarian cancer

Ovarian cancer typically presents at an advanced stage, and although the majority of cases initially respond well to platinum-based therapies, chemoresistance almost always occurs leading to a poor long-term prognosis. While various cellular autonomous mechanisms contribute to intrinsic or acquired platinum resistance, the tumour microenvironment (TME) plays a central role in resistance to therapy and disease progression by providing cancer stem cell niches, promoting tumour cell metabolic reprogramming, reducing chemotherapy drug perfusion and promoting an immunosuppressive environment. As such, the TME is an attractive therapeutic target which has been the focus of intense research in recent years. This review provides an overview of the unique ovarian cancer TME and its role in disease progression and therapy resistance, highlighting some of the latest preclinical and clinical data on TME-targeted therapies. In particular, it focuses on strategies targeting cancer-associated fibroblasts, tumour-associated macrophages, cancer stem cells and cancer cell metabolic vulnerabilities.

Application of Graphdiyne in Surface-Assisted Laser Desorption Ionization Mass Spectrometry

Graphdiyne (GD) is a new kind of carbon nanomaterial which has carbon-carbon triple bonds to form a layered structure. Here, we report the application of GD as the matrix for small molecule analysis in laser desorption ionization mass spectrometry (LDI MS). The GD matrix displayed two advantages: little background in the low mass range and good molecular ion signal in negative ion mode for many small molecules, e.g., fatty acids, amino acids, peptides, and drugs can be obtained in negative ion mode. By comparing the signal intensity of tetraphenylborate and juglone with and without GD existing, it was found that GD can enhance both of the desorption efficiency and ionization efficiency in LDI. Through analysis of the serum samples from liver cancer patients and healthy people, the GD-assisted LDI MS results showed that fatty acids could be used as potential biomarkers for the early diagnosis of liver cancer.

Value of 18F-FDG PET/CT Combined With Tumor Markers in the Evaluation of Ascites

OBJECTIVE

The purpose of this study is to investigate the value of ¹⁸F-FDG PET/CT combined with assessment of tumor markers in serum or ascites for the diagnosing and determining the prognosis of benign and malignant ascites.

MATERIALS AND METHODS

Patients with ascites of unknown cause who underwent evaluation with FDG PET/CT were included in this retrospective study. The maximum standardized uptake value (SUV_max) and levels of the tumor markers carbohydrate antigen-125 (CA-125) and carcinoembryonic antigen (CEA) in serum and ascites were recorded. The diagnostic values of FDG PET/CT, CEA and CA-125 levels in serum or ascites, and the combination of imaging plus tumor marker assessment were evaluated. Factors that were predictive of survival were also analyzed.

RESULTS

A total of 177 patients were included. Malignant ascites was eventually diagnosed in 104 patients, and benign ascites was diagnosed in the remaining 73 patients. With the use of FDG PET/CT, 44 patients (42.3%) were found to have primary tumors. The sensitivity, specificity, and accuracy of FDG PET/CT were 92.3%, 83.6%, and 88.7%, respectively. CA-125 levels in serum and ascites showed much better sensitivity than did CEA levels, but they showed significantly lower specificity. If the combination of tumor markers and FDG PET/CT was analyzed, the sensitivity, specificity, and accuracy of tumor markers in serum were 96.6%, 78.1%, and 88.7%, and those of tumor markers in ascites were 97.7%, 80.0%, and 90.4%, respectively. Sex may be an important factor affecting survival time (hazard ratio, 0.471; p = 0.004), but age, CEA level, and FDG PET/CT findings could not predict survival.

CONCLUSION

FDG PET/CT combined with assessment of tumor markers, especially CEA, increased the efficacy of diagnosis of ascites of unknown causes. Male sex conferred a poorer prognosis, whereas age, CEA level, and FDG uptake had no predictive significance in patients with malignant ascites.

The clinical significance of vascular endothelial growth factor in malignant ascites

Ascites can be caused by many kinds of diseases. Patients with undetermined ascites represent a diagnostic challenge. The aims of this study were to determine the diagnostic value of vascular endothelial growth factor (VEGF) in differentiation of malignant ascites from benign ascites and to investigate the clinical value of ascitic VEGF as an independent prognostic parameter. The study included 462 consecutive patients with malignant ascites and 550 patients with benign ascites, VEGF level in ascites were determined by a sandwich enzyme-linked immunosorbent assay. The survival rate was calculated by the Kaplan-Meier method and the log-rank test. Multivariate survival analysis was performed using the Cox hazards model. In our study, we found VEGF levels in malignant ascites (676.59 ± 303.86 pg/ml) were significantly higher than those in benign ascites (218.37 ± 98.15 pg/ml) (P < 0.001). Meanwhile, we also found that VEGF levels in malignant ascites from patients with ovarian cancer were higher than those with other cancers. Areas under the receiver operating characteristic (ROC) curves of ascitic VEGF was 0.940. At a cutoff value of 319.5 pg/ml, VEGF yielded a sensitivity of 89.2 % and a specificity of 88.4 %. Patients associated with the high-level VEGF value (≥613.38 pg/ml) in malignant ascites exhibited poor mean survival rates (8.3 ± 0.52 vs 15.11 ± 0.66 months, P < 0.001). In a multivariate Cox regression model, higher ascitic VEGF was an independent prognostic factor for overall survival. Planned subgroup analysis was performed for patients with tumor node metastasis (TNM) stage I. In the univariate analysis, only ascitic VEGF was associated with overall survival. VEGF was found to have a highly accurate sensitivity and specificity, suggesting that it could be considered as a new biomarker to differentiate malignant ascites from the benign one. The high level of VEGF value in malignant ascites may be used as an independent prognostic factor in patients with all stages of cancer.

Clinical significance of vascular endothelial growth factor and endostatin levels in the differential diagnosis of malignant and benign ascites

The aim of this study is to evaluate the performance of VEGF and endostatin levels in the differential diagnosis of malignant and benign ascites. The study included 101 consecutive patients with malignant ascites (55.2 ± 15.8 years, 63 men and 38 women) and 81 patients with benign ascites (53.0 ± 17.2 years, 51 men and 30 women). VEGF and endostatin levels in serum and ascites were determined by a sandwich enzyme immunoassay technique using a commercially available assay kit. The serum VEGF, ascites VEGF, and ascites endostatin levels of patients with malignant ascites were significantly higher than those in patients with benign ascites (P < 0.001), but there was no difference in serum endostatin levels between the two groups (P = 0.267). Ascites endostatin levels correlated positively with ascites VEGF (r = 0.5193, P < 0.01), and serum endostatin showed a low correlation with serum VEGF (r = 0.3291, P < 0.01) in patients with malignant ascites. Areas under the ROC curves of ascites VEGF, ascites endostatin, serum VEGF, and serum endostatin were 0.890, 0.815, 0.694, and 0.552, respectively. The combination of ascites VEGF and endostatin improved the sensitivity up to 90.1%, the specificity up to 87.7%, and the accuracy up to 89.0% in the differential diagnosis of malignant and benign ascites. VEGF and endostatin levels in ascites appear to be suitable for differentiating between malignant and benign ascites, which can be applied to clinical examination.

The Role of 18F-FDG PET/CT in the evaluation of Ascites of Undetermined Origin

The first aim of our study was to compare the role of (18)F-FDG PET/CT with that of CT alone in detecting the primary cause of ascites. A secondary aim was to compare the value of (18)F-FDG PET/CT with that of CT alone in detecting abdominal cavity metastasis. Finally, we analyzed the receiver-operating-characteristic (ROC) curves of maximal standardized uptake values (SUVmax), serum carcinoembryonic antigen, CA19-9, and CA12-5 for differential diagnostic abilities.

METHODS

The (18)F-FDG PET/CT scans of 40 patients with ascites of undetermined origin, including 30 patients with malignant diseases and 10 with benign lesions, were reviewed for the presence of ascites. Among the 40 patients, 34 had received their diagnosis by pathologic examination and 6 by clinical follow-up. We also assessed the (18)F-FDG PET/CT scans of 20 healthy volunteers for comparison. All (18)F-FDG PET/CT images were visually interpreted, and the SUVmax was measured. We compared the mean diameter of true-positive lesions with that of false-negative lesions. The diagnostic abilities of SUVmax, serum carcinoembryonic antigen, CA19-9, and CA12-5 were compared using the ROC curve.

RESULTS

The sensitivity, specificity, and accuracy of PET/CT in detecting the primary cause of ascites were 63.3% (19/30), 70.0% (7/10), and 65.0% (26/40), respectively, and those of CT alone were 36.7% (11/30), 80% (8/10), and 47.5% (19/40), respectively (sensitivity, P < 0.05). The sensitivity of PET/CT was higher than that of CT alone for detecting abdominal cavity metastasis (86.4% vs. 27.3%, P < 0.01). The SUVmax in patients with malignant primary and metastatic lesions was significantly higher than that in healthy volunteers and in patients with benign ascites (P < 0.05). The mean maximal diameter of false-negative lesions was significantly smaller than that of true-positive lesions (P < 0.05). In ROC analysis, the areas under the curve of SUVmax, serum carcinoembryonic antigen, CA19-9, and CA12-5 were 0.803 (P < 0.01), 0.773 (P < 0.05), 0.552 (P > 0.05), and 0.220 (P < 0.01), respectively.

CONCLUSION

(18)F-FDG PET/CT assisted in detecting the original cause of ascites. The differential diagnostic ability of (18)F-FDG PET/CT was superior to that of CT alone, tumor markers, and cytology. More attention should be paid to peritoneal tuberculosis, which can markedly accumulate (18)F-FDG and mimic peritoneal carcinoma.

Lipids changes in liver cancer

Liver is one of the most important organs in energy metabolism. Most plasma apolipoproteins and endogenous lipids and lipoproteins are synthesized in the liver. It depends on the integrity of liver cellular function, which ensures homeostasis of lipid and lipoprotein metabolism. When liver cancer occurs, these processes are impaired and the plasma lipid and lipoprotein patterns may be changed. Liver cancer is the fifth common malignant tumor worldwide, and is closely related to the infections of hepatitis B virus (HBV) and hepatitis C virus (HCV). HBV and HCV infections are quite common in China and other Southeast Asian countries. In addition, liver cancer is often followed by a procession of chronic hepatitis or cirrhosis, so that hepatic function is damaged obviously on these bases, which may significantly influence lipid and lipoprotein metabolism in vivo. In this review we summarize the clinical significance of lipid and lipoprotein metabolism under liver cancer.

Influence of liver cancer on lipid and lipoprotein metabolism

Liver plays a key role in the metabolism of plasma apolipoproteins, endogenous lipids and lipoproteins. Hepatocellular carcinoma (HCC) is one of the most common fatal malignant tumors in China and in other Southeast Asian countries. This has been attributed to the high incidence of hepatitis B infection. Hepatitis B proteins, such as the hepatitis B X protein (HBx) that is large hepatitis B surface protein could regulate transcription of many candidate genes for liver carcinogenesis. It has known that patients who suffered from acute hepatitis B could have lipid disorders such as decreased plasma level of high-density lipoproteins (HDL). Furthermore, aberrations of lipid metabolism are often seen in the chronic hepatitis B infection. Plasma lipid profiles could be changed under HCC. In majority of the reports in HCC, plasma levels of triglycerides (TG), cholesterol, free fatty acids (FFA), HDL, low-density lipoproteins (LDL), lipoprotein (a) (Lp(a)), apolipoprotein AI (apoAI) and apoB were slight to significantly decreased, however, in some cases plasma levels of TG and Lp(a) might be increased. It has been suggested that analysis of plasma levels of lipids, lipoproteins and apolipoproteins in the patients suffered from HCC reflects on the hepatic cellular impairment status. Studies revealed that alterations seen in the plasma levels of lipids, lipoproteins and apolipoproteins reflecting patients' pathologic conditions. Decreased serum levels of cholesterol and apoAI may indicate a poor prognosis. Human leukaemic cells and certain tumor tissues have a higher receptor-mediated uptake of HDL and LDL than the corresponding normal cells or tissues. LDL and HDL have therefore been proposed as a carrier for the water-insoluble anti-cancer agents.

Exploration of anthropological specimens by GC-MS and chemometrics

Anthropological specimens combine a variety of unfavorable characteristics, rendering their evaluation an analytical challenge. Their remarkable status is primarily based on two characteristics: (i) these very rare samples of human origin are testimonies of human history and are, therefore, available only in minute amounts for analytical purposes, and (ii) the analysis of these samples is extremely limited by the decomposition of molecules, which are easily detected in living organisms, such as nucleic acids and proteins, but are subject to rapid post-mortem decay. In this article, we review the methods and results of archaeometry, emphasizing the role of MS combined with chemometrics. Focusing on experimental results for fatty acid profiles, specimens from mummies from different civilizations were compared. Considering in particular the Tyrolean Iceman, the application of chemometric methods to GC-MS data recovers essential information about the preservation and the storage conditions of mummies.

Ascitic fluid analysis: the role of biochemistry and haematology

In specific settings, biochemical and haematological analysis of ascitic fluid may provide answers to important clinical questions. This review seeks to outline the value and limitations of ascitic fluid analysis and the main clinical scenarios in which it may be useful.