Cancer associated fibroblasts (CAF) and the extracellular matrix (ECM) produced by them have been recognized as key players in cancer biology and emerged as important targets for cancer treatment and drug discovery. Apart from their presence in stroma rich tumors, such as biliary, pancreatic and subtypes of hepatocellular cancer (HCC), both CAF and certain ECM components are also present in cancers without an overt intra-tumoral desmoplastic reaction. They support cancer development, growth, metastasis and resistance to chemo- or checkpoint inhibitor therapy by a multitude of mechanisms, including angiogenesis, ECM remodeling and active immunosuppression by secretion of tumor promoting and immune suppressive cytokines, chemokines and growth factors. CAF resemble activated hepatic stellate cells (HSC)/myofibroblasts, expressing α-smooth muscle actin and especially fibroblast activation protein (FAP). Apart from FAP, CAF also upregulate other functional cell surface proteins like platelet-derived growth factor receptor β (PDGFRβ) or the insulin-like growth factor receptor II (IGFRII). Notably, if formulated with adequate size and zeta potential, injected nanoparticles home preferentially to the liver. Several nanoparticular formulations were tested successfully to deliver dugs to activated HSC/myofibroblasts. Thus, surface modified nanocarriers with a cyclic peptide binding to the PDGFRβ or with mannose-6-phosphate binding to the IGFRII, effectively directed drug delivery to activated HSC/CAF in vivo. Even unguided nanohydrogel particles and lipoplexes loaded with siRNA demonstrated a high in vivo uptake and functional siRNA delivery in activated HSC, indicating that liver CAF/HSC are also addressed specifically by well-devised nanocarriers with optimized physicochemical properties. Therefore, CAF have become an attractive target for the development of stroma-based cancer therapies, especially in the liver.
Colorectal cancer (CRC) is one of the most common and fatal cancers worldwide. The carcinogenesis of CRC is based on a stepwise accumulation of mutations, leading either to an activation of oncogenes or a deactivation of suppressor genes. The loss of genetic stability triggers activation of proto-oncogenes (e.g., KRAS) and inactivation of tumor suppression genes, namely TP53 and APC, which together drive the transition from adenoma to adenocarcinoma. On the one hand, p53 mutations confer resistance to classical chemotherapy but, on the other hand, they open the door for immunotherapy, as p53-mutated tumors are rich in neoantigens. Aberrant function of the TP53 gene product, p53, also affects stromal and non-stromal cells in the tumor microenvironment. Cancer-associated fibroblasts together with other immunosuppressive cells become valuable assets for the tumor by p53-mediated tumor signaling. In this review, we address the manifold implications of p53 mutations in CRC regarding therapy, treatment response and personalized medicine.
Macrophages are the front soldiers of the innate immune system and are vital for immune defense, tumor surveillance, and tissue homeostasis. In chronic diseases, including cancer and liver fibrosis, macrophages can be forced into an immunosuppressive and profibrotic M2 phenotype. M2-type macrophages overexpress the mannose receptor CD206. Targeting these cells via CD206 and macrophage repolarization towards an immune stimulating and antifibrotic M1 phenotype through RNA interference represents an appealing therapeutic approach. We designed nanohydrogel particles equipped with mannose residues on the surface (ManNP) that delivered siRNA more efficiently to M2 polarized macrophages compared to their untargeted counterparts (NonNP) in vitro. The ManNP were then assessed for their in vivo targeting potential in mice with experimental liver fibrosis that is characterized by increased profibrotic (and immunosuppressive) M2-type macrophages. Double-labelled siRNA-loaded ManNP carrying two different near infrared labels for siRNA and ManNP showed good biocompatibility and robust uptake in fibrotic livers as assessed by in vivo near infrared imaging. siRNA–ManNP were highly colocalized with CD206+ M2-type macrophages on a cellular level, while untargeted NP (NonNP) showed little colocalization and were non-specifically taken up by other liver cells. ManNP did not induce hepatic inflammation or kidney dysfunction, as demonstrated by serological analysis. In conclusion, α-mannosyl-functionalized ManNP direct NP towards M2-type macrophages in diseased livers and prevent unspecific uptake in non-target cells. ManNP are promising vehicles for siRNA and other drugs for immunomodulatory treatment of liver fibrosis and liver cancer.
15 March 2022 in Proceedings of the National Academy of Sciences
Significance: Fibrosis is a consequence of most chronic liver diseases, but currently no approved antifibrotic treatment is available. M2-type macrophages drive fibrosis progression and prevent regression, even when effective causal therapies have been employed. M2-type macrophages activate a cascade of fibrogenic effector cells and can prevent removal of excess scar tissue. To switch these profibrogenic M2 to fibrolytic (regenerative) macrophages, we developed a pH-degradable, nanogel-based delivery system which can be covalently functionalized with the macrophage-repolarizing bisphosphonate alendronate. The nanogels efficiently deliver the clinically approved drug into hepatic nonparenchymal cells after intravenous administration. They do not eliminate macrophages but repolarize their phenotype and subsequently block fibrosis progression. This approach establishes a nanotherapeutic delivery platform to treat further M2-type macrophage-driven diseases, including cancer.
Background: Health literacy is a concept that refers to patients’ ability to manage their disease and the health system’s ability to guarantee access to services. There is evidence that health literacy impacts the health outcomes of patients with chronic diseases, but detailed information on this topic in patients with liver cirrhosis is scarce. It was the aim of this study to identify risk factors for poorer health literacy in patients with liver cirrhosis. Methods: 89 patients with liver cirrhosis were enrolled in this study and health literacy was measured using the Health Literacy Questionnaire (HLQ). Covert hepatic encephalopathy (CHE) was diagnosed clinically according to the West-Haven Criteria (HE grade 1) and the PHES (minimal HE). Depressive symptoms were assessed using the Hamilton Depression Rating Scale (HDRS). Based on the nine subscales of the HLQ, risk factors for poor health literacy were identified using linear regression models. Results: Normalized HLQ scores ranged between 65–76%, while appraisal of health information had lowest score (65%) and ability to actively engage with healthcare providers had highest score (76%). Multivariable regression analyses revealed an association of poorer health literacy and liver function as determined by MELD score and complications of liver cirrhosis such as a history of ascites or CHE. Additionally, we identified modifiable or preventable factors such as depressive symptoms, a history of falls, and active smoking as risk factors for poorer health literacy. Conclusion: Multiple factors seem to impact on health literacy in patients with liver cirrhosis. Addressing modifiable and preventable factors may improve health literacy.
The prevalence of metabolic risk factors and non-alcoholic fatty liver disease (NAFLD) is high among people living with HIV (PLWH). Data on the recently proposed definition of metabolic dysfunction-associated fatty liver disease (MAFLD) in PLWH receiving antiretroviral therapy (ART) remains unknown. A total of 282 PLWH were included in this cross-sectional cohort study. Vibration-controlled transient elastography (VCTE) was used to assess hepatic steatosis and fibrosis. MAFLD and its subgroups (overweight/obese, lean/normal weight, and type 2 diabetes) were defined according to a recently published international consensus statement. The majority of this cohort was male (n = 198, 70.2%), and the median age was 51.5 years. The median BMI was 25 kg/m2, and obesity was prevalent in 16.2% (n = 44). A total of 207 (73.4%) PLWH were classified as non-MAFLD while 75 (26.6%) qualified as MAFLD. The median CAP in the MAFLD group was 320 dB/m. PLWH with MAFLD showed a higher median LSM (p < 0.008) and were older (p < 0.005) compared to the non-MAFLD group. Overall, the metabolic risk profile was comparable between MAFLD and NAFLD. The majority of PLWH and MAFLD were overweight or obese (n = 58, 77.3%). The highest median LSM values were observed in the subgroup with MAFLD and type 2 diabetes. HIV-related parameters did not differ between non-MAFLD and MAFLD. The prevalence of MAFLD in PLWH is high and comparable to NAFLD. PLWH may be characterized according to the novel MAFLD criteria and its subgroups to identify patients at risk for chronic liver disease.