Histomorphological and inflammatory changes of white adipose tissue in gastrointestinal cancer patients with and without cachexia

CD3+/CD4+ cells combined with myosteatosis predict the prognosis in patients who underwent gastric cancer surgery

BACKGROUND

This study aimed to investigate the predictive capacity of lymphocyte subpopulations, sarcopenia and myosteatosis for clinical outcomes in patients who underwent gastric cancer surgery. Additionally, the prognostic significance of CD3+/CD4+ cells in conjunction with myosteatosis was explored.

METHODS

A cohort of 190 patients with gastric cancer who underwent surgery and received computed tomography scans between July 2016 and December 2017 at our institution was examined. Complete clinical information and peripheral lymphocyte subpopulations were available for all patients. A comprehensive array of statistical methodologies was employed to scrutinize variances in both clinical and pathological characteristics among patients, with the aim of identifying autonomous prognostic determinants requisite for the development of a nomogram. Subsequent assessment of the predictive efficacy of the nomogram was conducted via calibration curve analysis.

RESULTS

The study comprised a cohort of 190 participants, encompassing 126 males (66.32%) and 64 females (33.68%), with a mean age of 58.47 (±11.37) years. Patients were stratified into three groups based on CD3+/CD4+ cells and myosteatosis, with 24 in Group 1, 87 in Group 2 and 79 in Group 3. Notably, patients in the third group exhibited significantly shorter progression-free survival (PFS) (hazard ratio [HR] = 0.208, P < 0.001) and overall survival (OS) (HR = 0.193, P < 0.001). The subset of peripheral blood lymphocytes exhibited elevated levels of CD3+/CD4+ cells (HR = 2.485, P < 0.001) and heightened CD4+/CD8+ ratios (HR = 1.705, P = 0.038), whereas diminished CD19+ cell counts (HR = 0.210, P = 0.032) correlated with improved OS in patients. The individuals presenting with sarcopenia (HR = 4.089, P = 0.023) and myosteatosis (HR = 2.857, P < 0.001) displayed reduced OS. The multivariate Cox regression analysis showed that pathological tumour-node-metastasis stage, CD19+ cells, sarcopenia and CD3+/CD4+ cell-myosteatosis were identified as independent prognostic factors for PFS and OS in patients. The constructed nomograms for PFS and OS yielded C-index values of 0.839 (95% confidence interval [CI]: 0.798-0.880) and 0.836 (95% CI: 0.792-0.879), respectively. The calibration analysis demonstrated that the nomograms accurately predicted the 3- and 5-year survival rates of PFS and OS in patients.

CONCLUSIONS

Lymphocyte subsets, including CD3+/CD4+ cells, CD4+/CD8+ ratio and CD19+ cells, are indicative of clinical prognosis in gastric cancer surgery patients. Body composition parameters, such as sarcopenia and myosteatosis, are also associated with the patient's prognosis. The combination of CD3+/CD4+ cells with myosteatosis demonstrates enhanced prognostic value, enabling the identification of patients at high risk of post-operative metastasis and recurrence.

Circulating adipose-tissue miRNAs in gastrointestinal cancer patients and their association with the level and type of adiposity at body composition analysis

Background

Adipose tissue (AT) wasting in cancer is an early catabolic event with negative impact on outcomes. Circulating miRNAs may promote body weight loss and cachexia. We measured circulating miRNAs linked to AT alterations and compared their levels between i) gastrointestinal (GI) cancer patients and controls, ii) cachectic and non-cachectic cancer patients, and iii) according to adiposity level and its distribution.

Methods

Patients with GI cancer and subjects with benign diseases as controls were considered. Cachexia was assessed and adiposity evaluated by CT-scan for subcutaneous AT area (SAT), visceral AT area and the total AT area (TAT). MiRNAs involved were measured in plasma by RT-qPCR.

Results

37 naïve GI cancer patients and 14 controls were enrolled. Patients with cachexia presented with lower SAT compared to non-cachectic (p < 0.05). In cancer patients, we found higher levels of miR-26a, miR-128, miR-155 and miR-181a vs. controls (p < 0.05). Cancer patients with BMI < 25 kg/m2 showed higher levels of miR-26a vs. those with BMI ≥ 25 (p = 0.035). MiR-26a and miR-181a were higher in cachectic and non-cachectic vs. controls (p < 0.05). Differences between cachectic and controls were confirmed for miR-155 (p < 0.001) but not between non-cachectic vs. control (p = 0.072). MiR-155 was higher in cachectic patients with low TAT vs. those without cachexia and high TAT (p = 0.036).

Conclusion

Our data confirm a modulation of specific and different miRNAs involved in AT metabolism in cancer and cachexia. MiR-155 levels were higher in patients presenting with cachexia and low adiposity with implications in the pathogenic mechanisms and clinical consequences of GI cancer patients.

The role of interleukin-6 family cytokines in cancer cachexia

Cachexia is a wasting syndrome that manifests in more than half of all cancer patients. Cancer-associated cachexia negatively influences the survival of patients and their quality of life. It is characterized by a rapid loss of adipose and skeletal muscle tissues, which is partly mediated by inflammatory cytokines. Here, we explored the crucial roles of interleukin-6 (IL-6) family cytokines, including IL-6, leukemia inhibitory factor, and oncostatin M, in the development of cancer cachexia. These cytokines have been shown to exacerbate cachexia by promoting the wasting of adipose and muscle tissues, activating mechanisms that enhance lipolysis and proteolysis. Overlapping effects of the IL-6 family cytokines depend on janus kinase/signal transducer and activator of transcription 3 signaling. We argue that the blockade of these cytokine pathways individually may fail due to redundancy and future therapeutic approaches should target common downstream elements to yield effective clinical outcomes.

Tumoral acidosis promotes adipose tissue depletion by fostering adipocyte lipolysis

OBJECTIVE

Tumour progression drives profound alterations in host metabolism, such as adipose tissue depletion, an early event of cancer cachexia. As fatty acid consumption by cancer cells increases upon acidosis of the tumour microenvironment, we reasoned that fatty acids derived from distant adipose lipolysis may sustain tumour fatty acid craving, leading to the adipose tissue loss observed in cancer cachexia.

METHODS

To evaluate the pro-lipolytic capacities of acid-exposed cancer cells, primary mouse adipocytes from subcutaneous and visceral adipose tissue were exposed to pH-matched conditioned medium from human and murine acid-exposed cancer cells (pH 6.5), compared to naive cancer cells (pH 7.4). To further address the role of tumoral acidosis on adipose tissue loss, a pH-low insertion peptide was injected into tumour-bearing mice, and tumoral acidosis was neutralised with a sodium bicarbonate buffer. Prolipolytic mediators were identified by transcriptomic approaches and validated on murine and human adipocytes.

RESULTS

Here, we reveal that acid-exposed cancer cells promote lipolysis from subcutaneous and visceral adipocytes and that dampening acidosis in vivo inhibits adipose tissue depletion. We further found a set of well-known prolipolytic factors enhanced upon acidosis adaptation and unravelled a role for β-glucuronidase (GUSB) as a promising new actor in adipocyte lipolysis.

CONCLUSIONS

Tumoral acidosis promotes the mobilization of fatty acids derived from adipocytes via the release of soluble factors by cancer cells. Our work paves the way for therapeutic approaches aimed at tackling cachexia by targeting the tumour acidic compartment.

Cancer cachexia: biomarkers and the influence of age

Cancer cachexia (Ccx) is a complex metabolic condition characterized by pronounced muscle and fat wasting, systemic inflammation, weakness and fatigue. Up to 30% of cancer patients succumb directly to Ccx, yet therapies that effectively address this perturbed metabolic state are rare. In recent decades, several characteristics of Ccx have been established in mice and humans, of which we here highlight adipose tissue dysfunction, muscle wasting and systemic inflammation, as they are directly linked to biomarker discovery. To counteract cachexia pathogenesis as early as possible and mitigate its detrimental impact on anti-cancer treatments, identification and validation of clinically endorsed biomarkers assume paramount importance. Ageing was recently shown to affect both the validity of Ccx biomarkers and Ccx development, but the underlying mechanisms are still unknown. Thus, unravelling the intricate interplay between ageing and Ccx can help to counteract Ccx pathogenesis and tailor diagnostic and treatment strategies to individual needs.

Assessment of lipolysis biomarkers in adipose tissue of patients with gastrointestinal cancer

BACKGROUND

Adipose tissue metabolism may be impaired in patients with cancer. In particular, increased lipolysis was described in cancer-promoting adipose tissue atrophy. For this reason, we assessed the expression of the lipolysis-associated genes and proteins in subcutaneous adipose tissue (SAT) of gastrointestinal (GI) cancer patients compared to controls to verify their involvement in cancer, among different types of GI cancers, and in cachexia.

METHODS

We considered patients with GI cancer (gastric, pancreatic, and colorectal) at their first diagnosis, with/without cachexia, and controls with benign diseases. We collected SAT and total RNA was extracted and ATGL, HSL, PPARα, and MCP1 were analyzed by qRT-PCR. Western blot was performed to evaluate CGI-58, PLIN1 and PLIN5.

RESULTS

We found higher expression of ATGL and HSL in GI cancer patients with respect to controls (p ≤ 0.008) and a trend of increase for PPARα (p = 0.055). We found an upregulation of ATGL in GI cancer patients with cachexia (p = 0.033) and without cachexia (p = 0.017) vs controls. HSL was higher in patients with cachexia (p = 0.020) and without cachexia (p = 0.021), compared to controls. ATGL was upregulated in gastric cancer vs controls (p = 0.014) and higher HSL was found in gastric (p = 0.008) and in pancreatic cancer (p = 0.033) vs controls. At the protein level, we found higher CGI-58 in cancer vs controls (p = 0.019) and in cachectic vs controls (p = 0.029), as well as in gastric cancer vs controls (p = 0.027).

CONCLUSION

In our cohort of GI cancer patients, we found a modulation in the expression of genes and proteins involved in lipolysis, and differences were interestingly detected according to cancer type.

Cancer cachexia: molecular mechanisms and treatment strategies

Muscle wasting is a consequence of physiological changes or a pathology characterized by increased catabolic activity that leads to progressive loss of skeletal muscle mass and strength. Numerous diseases, including cancer, organ failure, infection, and aging-associated diseases, are associated with muscle wasting. Cancer cachexia is a multifactorial syndrome characterized by loss of skeletal muscle mass, with or without the loss of fat mass, resulting in functional impairment and reduced quality of life. It is caused by the upregulation of systemic inflammation and catabolic stimuli, leading to inhibition of protein synthesis and enhancement of muscle catabolism. Here, we summarize the complex molecular networks that regulate muscle mass and function. Moreover, we describe complex multi-organ roles in cancer cachexia. Although cachexia is one of the main causes of cancer-related deaths, there are still no approved drugs for cancer cachexia. Thus, we compiled recent ongoing pre-clinical and clinical trials and further discussed potential therapeutic approaches for cancer cachexia.

Metabolic and histomorphological changes of adipose tissue in cachexia

PURPOSE OF REVIEW

To describe the role of the main changes occurring in adipose tissue during cachexia and how these affects patient's outcomes, with a specific focus on cancer.

RECENT FINDINGS

In cachexia, the changes within the adipose tissue have been recently described as the presence of inflammatory infiltration (T-lymphocytes and macrophages), enhanced fibrosis, and the occurrence of beige adipocytes (i.e., browning). The latter one is a process driving cachexia enhancing thermogenesis, primarily via modulation of uncoupling protein 1. Also, increased lipolysis of white adipose tissue, especially in cancer, via higher expression of hormone sensible and adipose tissue triglyceride lipases, was detected in experimental models and in human adipose tissue. Other systemic metabolic alterations occur in association with changes in adiposity, including insulin resistance and increased inflammation, all conditions associated with a worse outcome. Moreover, these profound metabolic alterations were shown to be implicated in several consequences, including extreme and progressive unvoluntary body weight loss.

SUMMARY

Alterations in adiposity occur early during cachexia. Adipose tissue atrophy, as well as metabolic changes of white adipose tissues were observed to be pivotal in cachexia, and to be implicated in several clinical complications and poor prognosis.Further research is necessary to clarify the mechanisms underlying the loss of adiposity and therefore to identify novel therapeutic options to counteract this phenomenon in cachexia.

Reducing White Adipose Tissue Browning Using p38α MAPK Inhibitors Ameliorates Cancer-Associated Cachexia as Assessed by Magnetic Resonance Imaging

Background: Up to 80% of pancreatic cancer patients suffer from cachexia. White adipose tissue (WAT) browning caused by the tumorigenicity and progression aggravates the cancer-associated cachexia (CAC). Cancer-initiated changes in the protein-38 mitogen-activated protein kinases (p38 MAPK) pathway are likely involved in the development of CAC. Methods: p38 MAPK inhibitors, VCP979 or SB203580, were used in the in vitro and in vivo models of pancreatic cancer cachexia. Expression of uncoupling protein 1 (UCP1) in the p38 MARK pathway and the properties and level of white adipocytes were analyzed and correlated to browning, followed by immunohistochemistry and Western blotting validations. Changes in the volume and fat fraction of WAT in animals were monitored by magnetic resonance imaging (MRI). Results: The size of white adipocytes was increased after being treated with the p38 MAPK inhibitors, along with increase in the MRI-measured volume and fat fraction of WAT. Comparing two p38 MAPK inhibitors, the p38α subunit-specific inhibitor VCP979 had a better therapeutic effect than SB203580, which targets both p38α and β subunits. Conclusions: Blockade of p38 MAPK reduced the WAT browning that contributes to CAC. Thus, p38 MARK inhibitors can potentially be used as a therapy for treating CAC. Non-invasive MRI can also be applied to assess the progression and treatment responses of CAC.

Evaluation of Browning Markers in Subcutaneous Adipose Tissue of Newly Diagnosed Gastrointestinal Cancer Patients with and without Cachexia

Simple Summary

Cachexia occurs frequently in cancer patients with deep metabolic derangements. The browning of adipose tissue promotes thermogenesis and energy expenditure and, in cancer, has been considered a major determinant of adipose tissue atrophy. We evaluated the molecular phenotype of this phenomenon in the subcutaneous adipose tissue (SAT) of newly diagnosed gastrointestinal cancer patients compared to controls. We observed that the modulation of different markers of the browning of SAT in gastrointestinal cancer and, in particular, pancreatic cancer showed significant changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients. Our study highlights the relevance of browning in patients with cancer, in particular in those with pancreatic cancer. Understanding the browning phenomenon may allow us to counteract these metabolic alterations before the development of severe cachexia, which is characterized by deep adipose and muscle depletion, negatively affecting survival and quality of life.

Abstract

We assessed the molecular phenotype of the browning of white adipose tissue in newly diagnosed cancer patients and controls undergoing surgery for gastrointestinal tumors and for non-malignant diseases, respectively. We collected subcutaneous adipose tissue (SAT) samples and using RT-PCR, we analyzed the expression of markers of browning and using Western blot the protein levels of UCP1 and PGC1α. The Ucp1 mRNA levels were lower in cancer patients vs. controls (p = 0.01), whereas Cidea and Tmem26 mRNA levels were higher in cancer patients. We found higher PGC1α protein levels in patients vs. controls, while no differences were seen for UCP1. The Ucp1 expression was lower in cachectic and non-cachectic patients vs. controls, whereas Cidea expression was higher in cachectic and non-cachectic patients vs. controls. Pgc1α mRNA levels were higher in cachectic vs. non-cachectic patients (p = 0.03) vs. controls (p = 0.016). According to type of tumors, we did not observe differences in Cidea expression, whereas Pgc1α was higher in pancreatic cancer vs. colorectal and vs. controls. We observed the lower expression of Ucp1 in pancreatic and colorectal cancer vs. controls. We documented higher UCP1 protein levels in pancreatic cancer patients vs. colorectal (p = 0.002) and vs. controls (p = 0.031). PGC1α protein levels were higher in pancreatic cancer patients vs. controls. Different markers of the browning of SAT are modulated, and pancreatic cancer showed changes in UCP1 and PGC1α; PGC1α was highly expressed in cachectic patients, with clinical implications that should be further clarified.