Clonal hematopoiesis and myeloid malignancies: clonal dynamics and clinical implications

Steatotic liver disease in the context of hematological malignancies and anti-neoplastic chemotherapy

The rising prevalence of obesity-related illnesses, such as metabolic steatotic liver disease (MASLD), represents a significant global public health concern. This disease affects approximately 30 % of the adult population and is the result of metabolic abnormalities rather than alcohol consumption. Additionally, MASLD is associated with an increased risk of cardiovascular disease (CVD), chronic liver disease, and a variety of cancers, particularly gastrointestinal cancers. Clonal hematopoiesis (CH) is a biological state characterized by the expansion of a population of blood cells derived from a single mutated hematopoietic stem cell. The presence of CH in the absence of a diagnosed blood disorder or cytopenia is known as clonal hematopoiesis of indeterminate potential (CHIP), which itself increases the risk of hematological malignancies and CVD. Steatotic liver disease may also complicate the clinical course of cancer patients receiving antineoplastic agents, a condition referred to as chemotherapy induced steatohepatitis (CASH). This review will present an outline of the various aspects of MASLD, including complications. Furthermore, it will summarize the existing knowledge on the emerging association between CHIP and MASLD and present the available data on patient cases with concurrent MASLD and hematological neoplasms. Finally, it will provide a brief overview of the chemotherapeutic drugs associated with CASH, the underlying pathophysiologic mechanisms and their clinical implications.

Role of TET dioxygenases in the regulation of both normal and pathological hematopoiesis

The family of ten-eleven translocation dioxygenases (TETs) consists of TET1, TET2, and TET3. Although all TETs are expressed in hematopoietic tissues, only TET2 is commonly found to be mutated in age-related clonal hematopoiesis and hematopoietic malignancies. TET2 mutation causes abnormal epigenetic landscape changes and results in multiple stages of lineage commitment/differentiation defects as well as genetic instability in hematopoietic stem/progenitor cells (HSPCs). TET2 mutations are founder mutations (first hits) in approximately 40–50% of cases of TET2-mutant (TET2^MT) hematopoietic malignancies and are later hits in the remaining cases. In both situations, TET2^MT collaborates with co-occurring mutations to promote malignant transformation. In TET2^MT tumor cells, TET1 and TET3 partially compensate for TET2 activity and contribute to the pathogenesis of TET2^MT hematopoietic malignancies. Here we summarize the most recent research on TETs in regulating of both normal and pathogenic hematopoiesis. We review the concomitant mutations and aberrant signals in TET2^MT malignancies. We also discuss the molecular mechanisms by which concomitant mutations and aberrant signals determine lineage commitment in HSPCs and the identity of hematopoietic malignancies. Finally, we discuss potential strategies to treat TET2^MT hematopoietic malignancies, including reverting the methylation state of TET2 target genes and targeting the concomitant mutations and aberrant signals.