Cancer stem cell biomarkers and related signalling pathways

CALML3-AS1 enhances malignancies and stemness of small cell lung cancer cells through interacting with DAXX protein and promoting GLUT4-mediated aerobic glycolysis

The lncRNA CALML3 antisense RNA 1 (CALML3-AS1) is a biomarker for various cancers, including non-small cell lung cancer (NSCLC). However, the role of CALM3-AS1 in small cell lung cancer (SCLC) is still unclear. Here, we found that the CALML3-AS1 was upregulated in SCLC tissues and cells. SCLC cells (NCI-H69 and NCI-H466 cells) were transfected with small interfering RNA of CALML-AS1 (si-CALML3-AS1) and Death domain-associated protein (DAXX) (si-DAXX) or an overexpression vector of CALML-AS1 (dCas9-CALML3-AS1) and DAXX (dCas9-DAXX). The results showed that silencing CALML3-AS1 inhibited SCLC cell proliferation, colony formation, migration, invasion, and spheroid formation, and reduced the expression of stemness marker proteins (Nanog. Oct4, and Lin28). Moreover, silencing CALML3-AS1 reduced glycolysis rate, glucose utilization, and lactate production, and decreased the levels of key glycolytic regulatory proteins (GLUT1, GLUT4, HK2, and PKM2) in SCLC cells, while overexpression of CALML3-AS1 promoted malignant growth and stemness and enhanced glucose transporters type 4 (GLUT4)-mediated aerobic glycolysis by interacting with DAXX in NCI-H69 and NCI-H466 cells. Silencing DAXX or GLUT4, or treatment with 2-Deoxy-d-glucose (2-DG, a glycolysis inhibitor) reversed the effects of CALML3-AS1 overexpression on aerobic glycolysis, malignant growth, and stemness of SCLC cells. Finally, NCI-H69 cells transfected with CALML3-AS1, sh-CALML3-AS1, and sh-DAXX lentiviral vectors were subcutaneously injected into nude mice to construct xenograft models. Knockdown of CALML3-AS1 or DAXX inhibited tumor growth in SCLC in vivo. In conclusion, CALML3-AS1, an oncogene, promotes the malignancy and stemness of SCLC cells by interacting with DAXX to enhance GLUT4-mediated aerobic glycolysis, thereby promoting SCLC progression.

Metabolic Rate and Oxidative Stress as a Risk Factors in the Development of Colorectal Cancer

There is growing evidence that the body's energy expenditures constitute a significant risk factor for the development of most deadly diseases, including cancer. Our aim was to investigate the impact of basal metabolic rate (BMR) on the growth and progression of colorectal cancer (CRC). To do so, we used a unique model consisting of three lines of laboratory mice (Mus musculus) artificially selected for high (HBMR) and low (LBMR) basal metabolic rate and randomly bred individuals (non-selected, NSBMR). The experimental individuals were implanted with human colorectal cancer cells DLD-1. The variation in BMR between the lines allowed for testing the impact of whole-body metabolism on oxidative and antioxidant parameters in the liver throughout the cancerogenesis process. We investigated the dependence between metabolic values, reactive oxygen species (ROS) levels, and Kelch-like ECH-associated protein 1-based E3 ligase complexes (Keap1) gene activity in these animals. We found that the HBMR strain had a higher concentration of oxidative enzymes compared to the LBMR and NSBMR. Furthermore, the growth rate of CRC tumors was associated with alterations in the levels of oxidative stress enzymes and Keap1 expression in animals with a high metabolic rate. Our results indicate that a faster growth and development of CRC line DLD-1 is associated with enzymatic redox imbalance in animals with a high BMR.

Novel players in the development of chemoresistance in ovarian cancer: ovarian cancer stem cells, non-coding RNA and nuclear receptors

Ovarian cancer (OC) ranks as the fifth leading factor for female mortality globally, with a substantial burden of new cases and mortality recorded annually. Survival rates vary significantly based on the stage of diagnosis, with advanced stages posing significant challenges to treatment. OC is primarily categorized as epithelial, constituting approximately 90% of cases, and correct staging is essential for tailored treatment. The debulking followed by chemotherapy is the prevailing treatment, involving platinum-based drugs in combination with taxanes. However, the efficacy of chemotherapy is hindered by the development of chemoresistance, both acquired during treatment (acquired chemoresistance) and intrinsic to the patient (intrinsic chemoresistance). The emergence of chemoresistance leads to increased mortality rates, with many advanced patients experiencing disease relapse shortly after initial treatment. This review delves into the multifactorial nature of chemoresistance in OC, addressing mechanisms involving transport systems, apoptosis, DNA repair, and ovarian cancer stem cells (OCSCs). While previous research has identified genes associated with these mechanisms, the regulatory roles of non-coding RNA (ncRNA) and nuclear receptors in modulating gene expression to confer chemoresistance have remained poorly understood and underexplored. This comprehensive review aims to shed light on the genes linked to different chemoresistance mechanisms in OC and their intricate regulation by ncRNA and nuclear receptors. Specifically, we examine how these molecular players influence the chemoresistance mechanism. By exploring the interplay between these factors and gene expression regulation, this review seeks to provide a comprehensive mechanism driving chemoresistance in OC.