Thyroid cancer (TC) is a neoplasm with an increasing incidence worldwide. Its etiology is complex and based on a multi-layered interplay of factors. Among these, disorders of lipid metabolism have emerged as an important area of investigation. Cancer cells are metabolically reprogrammed to promote their rapid growth, proliferation, and survival. This reprogramming is associated with significant changes at the level of lipids, mainly fatty acids (FA), as they play a critical role in maintaining cell structure, facilitating signaling pathways, and providing energy. These lipid-related changes help cancer cells meet the increased demands of continued growth and division while adapting to the tumor microenvironment. In this review, we examine lipid metabolism at different stages, including synthesis, transport, and oxidation, in the context of TC and the effects of obesity and hormones on TC development. Recent scientific efforts have revealed disturbances in lipid homeostasis that are specific to thyroid cancer, opening up potential avenues for early detection and targeted therapeutic interventions. Understanding the intricate metabolic pathways involved in FA metabolism may provide insights into potential interventions to prevent cancer progression and mitigate its effects on surrounding tissues.

The development of techniques allowing the growth of primordial follicles to mature follicles in vitro has much potential for both reproductive medicine and developmental research. However, human primordial and preantral follicles fail to grow after isolation from the surrounding ovarian stroma. Granulosa cells, which normally undergo apoptosis after ovulation, contain a subpopulation of ovarian follicular cells remaining viable in vitro over prolonged periods when cultured in the presence of leukemia-inhibiting factor. However, when cultured as monolayers, they progressively lose all their characteristics, such as follicle-stimulating hormone receptor and cytochrome P450-aromatase. Here, we describe a three-dimensional culture system containing type I collagen, which, together with leukemia-inhibiting factor, allowed the survival and growth of a subpopulation of granulosa cells isolated from mature ovarian follicles and supported them to proliferate into spherical structures exhibiting steroidogenic capacity, as demonstrated by P450-aromatase and 3β-hydroxysteroid dehydrogenase. After transplantation into the ovaries of immunodeficient mice, these cells became localized preferentially within antral follicles and the prolonged expression of follicle-stimulating hormone receptor was confirmed as well. With this optimization of the culture conditions, an environment was created, which acts as a niche closely mimicking the development of early ovarian follicles in vitro.

RNA editing is one of the most prevalent and abundant forms of post-transcriptional RNA modification observed in normal physiological processes and often aberrant in diseases including cancer. RNA editing changes the sequences of mRNAs, making them different from the source DNA sequence. Edited mRNAs can produce editing-recoded protein isoforms that are functionally different from the corresponding genome-encoded protein isoforms. The major type of RNA editing in mammals occurs by enzymatic deamination of adenosine to inosine (A-to-I) within double-stranded RNAs (dsRNAs) or hairpins in pre-mRNA transcripts. Enzymes that catalyse these processes belong to the adenosine deaminase acting on RNA (ADAR) family. The vast majority of knowledge on the RNA editing landscape relevant to human disease has been acquired using in vitro cancer cell culture models. The limitation of such in vitro models, however, is that the physiological or disease relevance of results obtained is not necessarily obvious. In this review we focus on discussing in vivo occurring RNA editing events that have been identified in human cancer tissue using samples surgically resected or clinically retrieved from patients. We discuss how RNA editing events occurring in tumours in vivo can identify pathological signalling mechanisms relevant to human cancer physiology which is linked to the different stages of cancer progression including initiation, promotion, survival, proliferation, immune escape and metastasis.

Background: The association between COVID-19 infection and the development of autoimmune diseases is currently unknown, but there are already reports presenting induction of different autoantibodies by SARS-CoV-2 infection. Kikuchi-Fuimoto disease (KFD) as a form of histiocytic necrotizing lymphadenitis of unknown origin. Objective: Here we present a rare case of KFD with heart involvement after COVID-19 infection. To our best knowledge only a few cases of COVID-19-associated KFD were published so far. Based on presented case, we summarize the clinical course of KFD and its association with autoimmune diseases, as well we discuss the potential causes of perimyocarditis in this case. Methods: We reviewed the literature regarding cases of “Kikuchi-Fujimoto disease (KFD)” and “COVID-19” and then “KFD” and “heart” or “myocarditis” by searching medical journal databases written in English in PubMed and Google Scholar. Results: Only two cases of KFD after COVID infection have been described so far. Conclusion: SARS-CoV-2 infection can also be a new, potential causative agent of developing KFD.

Kikuchi-Fujimoto disease (KFD, histiocytic necrotizing lymphadenitis) is benign and self-limited cervical lymphadenopathy with accompanied mild fever. Disorder mostly affects young adults, rarely children mainly in Asia. The etiology of KFD is unknown but it is thought to be an autoimmune or inflammatory process triggered by viral infection in susceptible individuals. The minimal criteria required for the diagnosis of KFD include the presence of paracortical clusters of plasmacytoid dendritic cells admixed with karyorrhectic bodies and crescentic histiocytes. KFD does not require specific treatment except from antipyretics and anti-inflammatory medications. Here we present two new cases of KFD described in Poland together with the review of current literature.