The gut microbiota plays an essential role in maintaining immune homeostasis and influencing the immune landscape within the tumor microenvironment. This review aims to elucidate the interactions between gut microbiota and tumor immune dynamics, with a focus on colorectal cancer (CRC). The review spans foundational concepts of immuno-microbial interplay, factors influencing microbiome composition, and evidence linking gut microbiota to cancer immunotherapy outcomes. Gut microbiota modulates anti-cancer immunity through several mechanisms, including enhancement of immune surveillance and modulation of inflammatory responses. Specific microbial species and their metabolic byproducts can significantly influence the efficacy of cancer immunotherapies. Furthermore, microbial diversity within the gut microbiota correlates with clinical outcomes in CRC, suggesting potential as a valuable biomarker for predicting response to immunotherapy. Conclusions: Understanding the relationship between gut microbiota and tumor immune responses offers potential for novel therapeutic strategies and biomarker development. The gut microbiota not only influences the natural history and treatment response of CRC but also serves as a critical modulator of immune homeostasis and anti-cancer activity. Further exploration into the microbiome’s role could enhance the effectiveness of existing treatments and guide the development of new therapeutic modalities.

Colorectal cancer (CRC) is a major health burden worldwide and is the third most common type of cancer. The early detection and diagnosis of CRC is critical to improve patient outcomes. This review explores the intricate interplay between the tumor microenvironment, stromal interactions, and the progression and metastasis of colorectal cancer. The review begins by assessing the gut microbiome’s influence on CRC development, emphasizing its association with gut-associated lymphoid tissue (GALT). The role of the Wnt signaling pathway in CRC tumor stroma is scrutinized, elucidating its impact on disease progression. Tumor budding, its effect on tumor stroma, and the implications for patient prognosis are investigated. The review also identifies conserved oncogenic signatures (COS) within CRC stroma and explores their potential as therapeutic targets. Lastly, the seed and soil hypothesis is employed to contextualize metastasis, accentuating the significance of both tumor cells and the surrounding stroma in metastatic propensity. This review highlights the intricate interdependence between CRC cells and their microenvironment, providing valuable insights into prospective therapeutic approaches targeting tumor–stroma interactions.

Introduction. Colorectal cancer (CRC) is one of the most common oncological diseases, the pathogenesis of which is closely associated with the development of inflammation. The study of inflammation regulation, including the balance of pro- and antiinflammatory cytokines, is a promising topic for research, allowing for a deeper understanding of the pathogenesis of CRC and improving clinical approaches to the treatment for and diagnosis of this disease. This study investigates the altered secretion of proinflammatory cytokines, i.e., TNF-α and IL-1β, in CRC patients, aiming to elucidate immune dysregulation mechanisms. We sought to investigate the secretion characteristics of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β), in patients with CRC. Materials and methods. We enrolled 25 newly diagnosed CRC patients and 20 age- and sex-matched controls. Monocytes were isolated from the peripheral blood of participants using magnetic separation based on the CD14 marker. The isolated monocytes were cultured and subjected to dual stimulation with bacterial lipopolysaccharide at 24 hours and 7 days, followed by quantitative measurement of basal and stimulated cytokine levels using an enzyme-linked immunosorbent assay (ELISA). Results. We revealed a significant reduction in TNF-α secretion in CRC monocytes after initial LPS stimulation, with no subsequent recovery upon restimulation. In contrast, IL-1β secretion elevated markedly in CRC patients, particularly after restimulation. These results suggest an impaired TNF-α response and an exacerbated IL-1β response in CRC, indicating a potential immune tolerance mechanism that may contribute to tumor progression. The distinct cytokine dynamics observed point at complex immune dysregulation within the CRC microenvironment. Conclusion. The observed cytokine secretion patterns may indicate immune dysregulation in the microenvironment of CRC. Our study underscores the importance of understanding the specific roles of cytokines in CRC pathogenesis and highlights the potential for targeted therapeutic interventions to modulate these immune responses. Further research is necessary to explore the underlying signaling pathways and the broader implications of these findings for CRC treatment strategies. This work provides critical insights into the pro-inflammatory cytokine profiles in CRC, advancing our understanding of the immune landscape in cancer and opening new avenues for therapeutic exploration. Keywords: colorectal cancer, cytokines, tumor necrosis factor-alpha, interleukin-1 beta, immune tolerance

Cardiac involvement is the most important factor determining prognosis in patients with systemic amyloidosis. This retrospective observational study of 98 patients with amyloidosis was undertaken to assess the amyloid types that are most likely to affect the heart, describe histopathological and clinical features of cardiac amyloidosis, and estimate the number of cases not diagnosed clinically prior to death. All cases were divided into two groups based on the method of examination. The first group included 46 patients with cardiac amyloidosis revealed via endomyocardial biopsies (EMBs), and the second group included 52 amyloidosis patients who did not undergo EMBs, in whom cardiac involvement was identified only at autopsy. The EMBs demonstrated that AL amyloidosis was detected in 21 (46%) specimens, ATTR amyloid in 24 cases (52%), and AA amyloid in 1 case (2%). The autopsy reports defined 15 (46%) cases of AL amyloidosis, 21 (40%) of ATTR and 16 (31%) of AA amyloidosis. It should be noted that a clinical diagnosis of ATTR amyloidosis was made only in 9.5% of patients from the autopsy group, suggesting that ATTR may be an underdiagnosed cause of heart failure in elderly patients. The most intense amyloid deposits were determined in biopsy and autopsy specimens of patients with AL kappa amyloidosis, underlying a poorer prognosis.

This review offers an in-depth analysis of mitochondrial DNA (mtDNA) mutations in colorectal cancer stem cells (CSCs), emphasizing their significant impact on tumor dynamics and potential therapeutic strategies. CSCs are a special subpopulation due to their unique capabilities for self-renewal, differentiation, and resistance to conventional therapies. Given that CSCs significantly differ from other tumor cell subpopulations, particularly in their metabolic properties, and considering that colorectal cancer is a malignancy characterized by mitochondrial dysfunction, this review aims to put together existing data on the differences in the mitochondrial genome of CSCs compared to other colorectal tumor cell subpopulations. Additionally, the review seeks to explore the potential roles of these differences and to identify new ideas for therapeutic strategies. Key topics include the identification and properties of CSCs in colorectal cancer, the distinctive features of the mitochondrial genome, and the functional consequences of mtDNA mutations. The review hypothesizes that CSCs rely on well-functioning mitochondria for crucial aspects like energy production; yet, mtDNA mutations can lead to mitochondrial dysfunction, altering CSC characteristics and influencing cancer progression. The article discusses emerging therapeutic approaches targeting mitochondrial function in colorectal CSCs and highlights the need for advanced research, including the development of preclinical models and exploration of targeted therapies, to improve the understanding and treatment of colorectal cancer.

Introduction. The article studies excised scars on the uterus after Gusakov’s and Stark’s cesarean sections, with an assessment of the impact of gynecological and extragenital diseases on the viability of the scar. Cesarean scar pregnancy is known to be a frequent indication for surgical delivery. However, if the uterine scar is stable, it is advisable to deliver the baby through the natural birth canal. At present, natural delivery of pregnant women with a scar on the uterus through natural childbirth is an important task in modern obstetrics. Thus, the aim of our study was to perform a multifaceted clinical and morphological evaluation of uterine scars after cesarean section in patients with gynecological and extragenital diseases. Materials and methods. We analyzed samples of scar tissue on the uterus after cesarean section performed in 68 patients. A pathomorphological study was carried out with Mallory staining with hematoxylin and eosin. Immunohistochemical study was performed with antibodies to collagen IV, vimentin, desmin, and von Willebrand factor. Results. In 56 out of 68 puerperas (82.3%), the scars on the uterus were stable with complete replacement of the defect with muscle (63.2%) or connective tissue (19.1%), regardless of the operation duration and the suturing technique. This was confirmed by additional diagnostic methods (Mallory stain and IHC with an antibody panel). We found that connective tissue dysplasia, which is indirectly indicated by the presence of myopia in 5 patients with wealthy fibrous scars, can affect excessive connective tissue in the scar. Twelve out of 68 puerperas (17.6%) had the scars (according to pathomorphological criteria) with severe edema, hemorrhages, tissue with different fibers, and uneven thinning. These patients had extragenital diseases, such as type 2 diabetes mellitus (36.4%) and anemia (18.2%). We did not reveal any influence of existing gynecological diseases on the scar stability. Conclusion. The healing of the postoperative uterine wound was mostly influenced by extragenital diseases (type 2 diabetes mellitus, anemia, connective tissue dysplasia) associated with metabolic disorders and having systemic effects on the body. The Gusakov’s or Stark’s incision closure techniques did not affect the quality of the scar. However, the scars after cesarean section using the Stark incision technique had significantly more connective than muscular tissue. Keywords: cesarean section, incompetent uterine scar, type 2 diabetes mellitus, anemia, connective tissue dysplasia, pathological examination, immunohistochemical study