Role of Leptin and Adiponectin in Carcinogenesis

Hormones produced by adipocytes, leptin and adiponectin, are associated with the process of carcinogenesis. Both of these adipokines have well-proven oncologic potential and can affect many aspects of tumorigenesis, from initiation and primary tumor growth to metastatic progression. Involvement in the formation of cancer includes interactions with the tumor microenvironment and its components, such as tumor-associated macrophages, cancer-associated fibroblasts, extracellular matrix and matrix metalloproteinases. Furthermore, these adipokines participate in the epithelial-mesenchymal transition and connect to angiogenesis, which is critical for cancer invasiveness and cancer cell migration. In addition, an enormous amount of evidence has demonstrated that altered concentrations of these adipocyte-derived hormones and the expression of their receptors in tumors are associated with poor prognosis in various types of cancer. Therefore, leptin and adiponectin dysfunction play a prominent role in cancer and impact tumor invasion and metastasis in different ways. This review clearly and comprehensively summarizes the recent findings and presents the role of leptin and adiponectin in cancer initiation, promotion and progression, focusing on associations with the tumor microenvironment and its components as well as roles in the epithelial-mesenchymal transition and angiogenesis.

Assessment of the Role of Leptin and Adiponectinas Biomarkers in Pancreatic Neuroendocrine Neoplasms

Data on the possible connection between circulating adipokines and PanNENs are limited. This novel study aimed to assess the serum levels of leptin and adiponectin and their ratio in patients with PanNENs and to evaluate the possible relationship between them and PanNEN's grade or stage, including the presence of metastases. The study group consisted of PanNENs (n = 83), and healthy controls (n = 39). Leptin and adiponectin measurement by an ELISA assay was undertaken in the entire cohort. The serum concentration of adiponectin was significantly higher in the control group compared to the study group (p < 0.001). The concentration of leptin and adiponectin was significantly higher in females than in males (p < 0.01). Anincreased leptin-adiponectin ratio was observed in well-differentiated PanNENs (G1) vs. moderatelydifferentiated PanNENs (G2) (p < 0.05). An increased leptin-adiponectin ratio was found in PanNENs with Ki-67 < 3% vs. Ki-67 ≥ 3% (p < 0.05). PanNENs with distal disease presented lower leptin levels (p < 0.001) and a decreased leptin-adiponectin ratio (p < 0.01) compared with the localized disease group. Leptin, adiponectin, and the leptin-adiponectin ratio may serve as potential diagnostic, prognostic, and predictive biomarkers for PanNENs. Leptin levels and the leptin-adiponectin ratio may play an important role as predictors of malignancy and metastasis in PanNENs.

Selected Serum Biomarkers (Leptin, Chromogranin A, CA19-9, CEA) in Patients with Pancreatic Neuroendocrine Neoplasm and Associations with Metabolic Syndrome

Metabolic abnormalities are well-known risk factors for many cancers, even though no clearly established link with pancreatic neuroendocrine neoplasms (PanNENs) has yet been investigated. This research aimed to assess the serum levels of leptin, chromogranin A (CgA), carbohydrate antigen 19-9 (CA19-9), and carcinoembryonic antigen (CEA) in patients with PanNENs and to search for associations between PanNENs, these selected serum biomarkers, and metabolic abnormalities in the form of metabolic syndrome (MS). Second, we aimed to investigate whether MS increases the risk of PanNENs. The serum concentrations of biomarkers, metabolic parameters (glucose, cholesterol, triglycerides), and anthropometric measurements (weight, height, BMI) were assessed in 106 patients with PanNENs and 40 healthy volunteers. Patients with PanNENs showed higher serum concentrations of CA19-9, CEA, and CgA in comparison to controls (p < 0.001, p = 0.042, and p = 0.025, respectively). Statistically significant differences in CEA levels were found in PanNENs patients with MS (p = 0.043). PanNENs patients with a BMI ≥ 25 kg/m² and who were female exhibited significantly higher leptin levels (p < 0.001 and p = 0.013, respectively). Additionally, this study reflects the importance of determining markers. Future research should focus on understanding the impact of metabolic disturbances on PanNENs and accounting for the relationship between PanNENs and MS, such as other malignancies.