Hexavalent chromium induces centrosome amplification through ROS-ATF6-PLK4 pathway in colon cancer cells

ATF family members as therapeutic targets in cancer: From mechanisms to pharmacological interventions

The activating transcription factor (ATF)/ cAMP-response element binding protein (CREB) family represents a large group of basic zone leucine zip (bZIP) transcription factors (TFs) with a variety of physiological functions, such as endoplasmic reticulum (ER) stress, amino acid stress, heat stress, oxidative stress, integrated stress response (ISR) and thus inducing cell survival or apoptosis. Interestingly, ATF family has been increasingly implicated in autophagy and ferroptosis in recent years. Thus, the ATF family is important for homeostasis and its dysregulation may promote disease progression including cancer. Current therapeutic approaches to modulate the ATF family include direct modulators, upstream modulators, post-translational modifications (PTMs) modulators. This review summarizes the structural domain and the PTMs feature of the ATF/CREB family and comprehensively explores the molecular regulatory mechanisms. On this basis, their pathways affecting proliferation, metastasis, and drug resistance in various types of cancer cells are sorted out and discussed. We then systematically summarize the status of the therapeutic applications of existing ATF family modulators and finally look forward to the future prospect of clinical applications in the treatment of tumors by modulating the ATF family.

Cadmium promotes the binding and centrosomal translocation of CCDC85C and PLK4 via ROS-GCLM pathway to trigger centrosome amplification in colon cancer cells

Cadmium (Cd) is a prevalent heavy metal contaminant that can cause centrosome amplification (CA) and cancer. Since CA can initiate tumorigenesis, it is plausible that cadmium initiates tumorigenesis via CA. The present study investigated the signaling pathways underlying CA by Cd. Our findings confirmed that sub-toxic concentrations of Cd could induce CA in the HCT116 colon cancer cells, and revealed that reactive oxygen species (ROS), GCLM, CCDC85C and PLK4 were the signaling molecules that formed a pathway of ROS-GCLM-CCDC85C-PLK4. Cd not only increased the protein levels of CCDC85C and PLK4, but also promoted their distribution to the centrosomes. Molecular docking analysis revealed that CCDC85C and PLK4 had the binding potential. Indeed, antibodies against CCDC85C and PLK4 were able to pull down PLK4 and CCDC85C, respectively. Knockdown of CCDC85C decreased the Cd-promoted centrosomal distribution of PLK4. Similarly, knockdown of PLK4 reduced the centrosomal distribution of CCDC85C. Our results suggest that Cd activates ROS-GCLM pathway that triggers the expression of and binding between CCDC85C and PLK4, and promotes the translocation of CCDC85C-PLK4 complex to the centrosomes, which eventually leads to CA.

Aluminium bioaccumulation in colon cancer, impinging on epithelial-mesenchymal-transition and cell death

We investigated the presence of aluminium (Al) in human colon cancer samples and its potential association with biological processes involved in cancer progression, such as epithelial to mesenchymal transition (EMT) and cell death. 25 consecutive colon samples were collected from patients undergoing colonic resection. Both neoplastic and normal mucosa were collected from each patient and subjected to histological, ultrastructural and immunohistochemical analyses. Moreover, colon samples from two Al-positive patients underwent multi-omic analyses, including whole genome sequencing and RNA sequencing (RNAseq). Morin staining, used to identify in situ aluminium bioaccumulation, showed the presence of Al in tumor areas of 24 % of patients. Transmission electron microscopy and energy-dispersive X-ray microanalysis confirmed the presence of Al specifically in intracytoplasmic electrondense nanodeposits adjacent to mitochondria of colon cancer cells. Immunohistochemical analyses for vimentin and nuclear β-catenin were performed to highlight the occurrence of the EMT phenomenon in association to Al bioaccumulation. Al-positive samples showed a significant increase in both the number of vimentin-positive and nuclear β-catenin-positive cancer cells compared to Al-negative samples. Moreover, Al-positive samples exhibited a significant decrease in the number of apoptotic cells, as well as the expression of the anti-apoptotic molecule BCL-2. Multi-omic analyses revealed a higher tumor mutational burden (TMB) in Al-positive colon cancers (n = 2) compared to a control cohort (n = 100). Additionally, somatic mutations in genes associated with EMT (GATA3) and apoptosis (TP53) were observed in Al-positive colon cancers. In conclusion, this study provides the first evidence of Al bioaccumulation in colon cancer and its potential role in modulating molecular pathways involved in cancer progression, such as EMT and apoptosis. Understanding the molecular mechanisms underlying Al toxicity might contribute to improve strategies for prevention, early detection, and targeted therapies for the management of colon cancer patients.

The impact of toxic metal bioaccumulation on colorectal cancer: Unravelling the unexplored connection

Colorectal cancer is a major public health concern, with increasing incidence and mortality rates worldwide. Environmental factors, including exposure to toxic metals, such as lead, chromium, cadmium, aluminium, copper, arsenic and mercury, have been suggested to play a significant role in the development and progression of this neoplasia. In particular, the bioaccumulation of toxic metals can play a significant role in colorectal cancer by regulating biological phenomenon associated to both cancer occurrence and progression, such as cell death and proliferation. Also, frequently these metals can induce DNA mutations in well-known oncogenes. This review provides a critical analysis of the current evidence, highlighting the need for further research to fully grasp the complex interplay between toxic metal bioaccumulation and colorectal cancer. Understanding the contribution of toxic metals to colorectal cancer occurrence and progression is essential for the development of targeted preventive strategies and social interventions, with the ultimate goal of reducing the burden of this disease.

N-Acetylcysteine, an ROS Inhibitor, Alleviates the Pathophysiology of Hyperthyroidism-Induced Cardiomyopathy via the ROS/Ca2+ Pathway

Hyperthyroidism is common and can induce cardiomyopathy, but there is no effective therapeutic strategy. The purpose of this study was to investigate the molecular mechanism of hyperthyroidism-induced cardiomyopathy (HTC) and the effect of N-acetylcysteine (NAC), an ROS inhibitor, on the pathophysiology of HTC in vivo and in vitro. Compared with those in the control groups in vivo and in vitro, TT3 and TT4 were significantly increased, the structure of myocardial cells was enlarged and disordered, and interstitial fibrosis and the apoptosis of myocardial cells were markedly increased in the L-Thy group. The ROS and inflammatory response were increased in the hyperthyroidism group. In the NAC group, the contents of TT3 and TT4 were decreased, the myocardial cell structure was slightly disturbed, fibrosis and apoptosis were significantly reduced, and the ROS level and inflammatory response were significantly reduced. Interestingly, L-Thy decreased the viability of fibroblasts and H9c2 cells, suggesting that L-Thy-induced fibrosis was not caused by the proliferation of fibroblasts. The molecular mechanism of HTC could be explained by the fact that L-Thy could cause cardiac hypertrophy, inflammation, and fibrosis by regulating the Ca2+/calpain/Rcan1-dependent signalling pathway, the Ca2+/Rcan1/NF-κB/p65-dependent signalling pathway, and the Ca2+/ROS/Bcl-2/caspase-3-dependent signalling pathway. In conclusion, NAC can alleviate the pathophysiology of hyperthyroidism-induced cardiomyopathy, probably by regulating the ROS/Ca2+-dependent pathway.