Tumor microenvironment: Sanctuary of the devil

Normal and Leukemic Stem Cell Niches: Insights and Therapeutic Opportunities

UNLABELLED
Mesenchymal cells of the tumor-associated stroma are critical determinants of carcinoma cell behavior. We focus here on interactions of carcinoma cells with mesenchymal stem cells (MSC), which are recruited to the tumor stroma and, once present, are able to influence the phenotype of the carcinoma cells. We find that carcinoma cell-derived interleukin-1 (IL-1) induces prostaglandin E(2) (PGE(2)) secretion by MSCs. The resulting PGE(2) operates in an autocrine manner, cooperating with ongoing paracrine IL-1 signaling, to induce expression of a group of cytokines by the MSCs. The PGE(2) and cytokines then proceed to act in a paracrine fashion on the carcinoma cells to induce activation of β-catenin signaling and formation of cancer stem cells. These observations indicate that MSCs and derived cell types create a cancer stem cell niche to enable tumor progression via release of PGE(2) and cytokines.


SIGNIFICANCE
Although PGE2 has been implicated time and again in fostering tumorigenesis, its effects on carcinoma cells that contribute specifically to tumor formation are poorly understood. Here we show that tumor cells are able to elicit a strong induction of the COX-2/microsomal prostaglandin-E synthase-1 (mPGES-1)/PGE(2) axis in MSCs recruited to the tumor-associated stroma by releasing IL-1, which in turn elicits a mesenchymal/stem cell–like phenotype in the carcinoma cells.

Cancer-Stimulated Mesenchymal Stem Cells Create a Carcinoma Stem Cell Niche via Prostaglandin E

Haematological malignancies were previously thought to be driven solely by genetic or epigenetic lesions within haematopoietic cells. However, the niches that maintain and regulate daily production of blood and immune cells are now increasingly being recognized as having an important role in the pathogenesis and chemoresistance of haematological malignancies. Within haematopoietic cells, the accumulation of a small number of recurrent mutations initiates malignancy. Concomitantly, specific alterations of the niches, which support haematopoietic stem cells and their progeny, can act as predisposition events, facilitating mutant haematopoietic cell survival and expansion as well as contributing to malignancy progression and providing protection of malignant cells from chemotherapy, ultimately leading to relapse. In this Perspective, we summarize our current understanding of the composition and function of the specialized haematopoietic niches of the bone marrow during health and disease. We discuss disease mechanisms (rather than malignancy subtypes) to provide a comprehensive description of key niche-associated pathways that are shared across multiple haematological malignancies. These mechanisms include primary driver mutations in bone marrow niche cells, changes associated with increased hypoxia, angiogenesis and inflammation as well as metabolic reprogramming by stromal niche cells. Consequently, remodelling of bone marrow niches can facilitate immune evasion and activation of survival pathways favouring malignant haematopoietic cell maintenance, defence against excessive reactive oxygen species and protection from chemotherapy. Lastly, we suggest guidelines for the handling and biobanking of patient samples and analysis of the niche to ensure that basic research identifying therapeutic targets can be more efficiently translated to the clinic. The hope is that integrating knowledge of how bone marrow niches contribute to haematological disease predisposition, initiation, progression and response to therapy into future clinical practice will likely improve the treatment of these disorders.

Bone marrow niches in haematological malignancies.

Molecular biomarkers in acute myeloid leukemia

Reciprocal leukemia-stroma VCAM-1/VLA-4-dependent activation of NF-κB mediates chemoresistance.

mediates chemoresistance B κ Reciprocal leukemia-stroma VCAM-1/VLA-4-dependent activation of NF-

Use of honokiol in lung cancer therapy: a mini review of its pharmacological mechanism.

Background Understanding the effects of demographic drivers on lung cancer mortality trends is critical for lung cancer control. We have examined the drivers of lung cancer mortality at the global, regional, and national levels. Methods Data on lung cancer death and mortality were extracted from the Global Burden of Disease (GBD) 2019. Estimated annual percentage change (EAPC) in the age-standardized mortality rate (ASMR) for lung cancer and all-cause mortality were calculated to measure temporal trends in lung cancer from 1990 to 2019. Decomposition analysis was used to analyze the contributions of epidemiological and demographic drivers to lung cancer mortality. Results Despite a non-significant decrease in ASMR [EAPC = −0.31, 95% confidence interval (CI): −1.1 to 0.49], the number of deaths from lung cancer increased by 91.8% [95% uncertainty interval (UI): 74.5–109.0%] between 1990 and 2019. This increase was due to the changes in the number of deaths attributable to population aging (59.6%), population growth (56.7%), and non-GBD risks (3.49%) compared with 1990 data. Conversely, the number of lung cancer deaths due to GBD risks decreased by 19.8%, mainly due to tobacco (−12.66%), occupational risks (−3.52%), and air pollution (−3.47%). More lung cancer deaths (1.83%) were observed in most regions, which were due to high fasting plasma glucose levels. The temporal trend of lung cancer ASMR and the patterns of demographic drivers varied by region and gender. Significant associations were observed between the contributions of population growth, GBD risks and non-GBD risks (negative), population aging (positive), and ASMR in 1990, the sociodemographic index (SDI), and the human development index (HDI) in 2019. Conclusion Population aging and population growth increased global lung cancer deaths from 1990 to 2019, despite a decrease in age-specific lung cancer death rates due to GBD risks in most regions. A tailored strategy is needed to reduce the increasing burden of lung cancer due to outpacing demographic drivers of epidemiological change globally and in most regions, taking into account region- or gender-specific risk patterns.

https://www.frontiersin.org/articles/10.3389/fpubh.2023.1054200/pdf

Ying Wang

Papers

Reciprocal leukemia-stroma VCAM-1/VLA-4-dependent activation of NF-κB mediates chemoresistance.

mediates chemoresistance B κ Reciprocal leukemia-stroma VCAM-1/VLA-4-dependent activation of NF-

Use of honokiol in lung cancer therapy: a mini review of its pharmacological mechanism.

Epidemiological and demographic drivers of lung cancer mortality from 1990 to 2019: results from the global burden of disease study 2019