Induction of epithelial-mesenchymal transition (EMT) in breast cancer cells is calcium signal dependent

Hypoxia-induced TRPM7 promotes glycolytic metabolism and progression in hepatocellular carcinoma

BACKGROUND

Hypoxia disrupts glucose metabolism in hepatocellular carcinoma (HCC). Transient receptor potential cation channel, subfamily M, member 7 (TRPM7) plays an ontogenetic role. Thus, we aimed to explore the regulation of TRPM7 by hypoxia-induced factor (HIF) and its underlying mechanisms in HCC.

METHODS

hypoxia was induced in multiple HCC cells using 1% O2 or CoCl2 treatment, and subsequently blocked using siRNAs targeting HIF-1α or HIF-2α as well as a HIF-1α protein synthesis inhibitor. The levels of HIF-1α and TRPM7 were assessed using quantitative PCR (qPCR) and Western blot analysis. Chromatin immunoprecipitation (ChIP) and luciferase assays were performed to observe the regulation of TRPM7 promoter regions by HIF-1α. A PCR array was utilized to screen glucose metabolism-related enzymes in HEK293 cells overexpressing TRPM7 induced by tetracycline, and then verified in TRPM7-overexpressed huh7 cells. Finally, CCK-8, transwell, scratch and tumor formation experiments in nude mice were conducted to examine the effect of TRPM7 on proliferation and metastasis in HCC.

RESULTS

Exposure to hypoxia led to increase the levels of TRPM7 and HIF-1α in HCC cells, which were inhibited by HIF-1α siRNA or enhanced by HIF-1α overexpression. HIF-1α directly bound to two hypoxia response elements (HREs) in the TRPM7 promoter. Several glycolytic metabolism-related enzymes, were simultaneously upregulated in HEK293 and huh7 cells overexpressing TRPM7 during hypoxia. In vitro and in vivo experiments demonstrated that TRPM7 promoted the proliferation and metastasis of HCC cells.

CONCLUSIONS

TRPM7 was directly transcriptionally regulated by HIF-1α, leading to glycolytic metabolic reprogramming and the promotion of HCC proliferation and metastasis in vitro and in vivo. Our findings suggest that TRPM7 might be a potential diagnostic indicator and therapeutic target for HCC.

Inhibition of oxidative stress-induced epithelial-mesenchymal transition in retinal pigment epithelial cells of age-related macular degeneration model by suppressing ERK activation

INTRODUCTION

Epithelial-mesenchymal transition (EMT) of retinal pigment epithelial (RPE) cells is related to the pathogenesis of various retinopathies including age-related macular degeneration (AMD). Oxidative stress is the major factor that induces degeneration of RPE cells associated with the etiology of AMD.

OBJECTIVES

Sodium iodate (NaIO3) generates intracellular reactive oxygen species (ROS) and is widely used to establish a model of AMD due to the selective induction of retinal degeneration. This study was performed to clarify the effects of multiple NaIO3-stimulated signaling pathways on EMT in RPE cells.

METHODS

The EMT characteristics in NaIO3-treated human ARPE-19 cells and RPE cells of the mouse eyes were analyzed. Multiple oxidative stress-induced modulators were investigated and the effects of pre-treatment with Ca2+ chelator, extracellular signal-related kinase (ERK) inhibitor, or epidermal growth factor receptor (EGFR) inhibitor on NaIO3-induced EMT were determined. The efficacy of post-treatment with ERK inhibitor on the regulation of NaIO3-induced signaling pathways was dissected and its role in retinal thickness and morphology was evaluated by using histological cross-sections and spectral domain optical coherence tomography.

RESULTS

We found that NaIO3 induced EMT in ARPE-19 cells and in RPE cells of the mouse eyes. The intracellular ROS, Ca2+, endoplasmic reticulum (ER) stress marker, phospho-ERK, and phospho-EGFR were increased in NaIO3-stimulated cells. Our results showed that pre-treatment with Ca2+ chelator, ERK inhibitor, or EGFR inhibitor decreased NaIO3-induced EMT, interestingly, the inhibition of ERK displayed the most prominent effect. Furthermore, post-treatment with FR180204, a specific ERK inhibitor, reduced intracellular ROS and Ca2+ levels, downregulated phospho-EGFR and ER stress marker, attenuated EMT of RPE cells, and prevented structural disorder of the retina induced by NaIO3.

CONCLUSIONS

ERK is a crucial regulator of multiple NaIO3-induced signaling pathways that coordinate EMT program in RPE cells. Inhibition of ERK may be a potential therapeutic strategy for the treatment of AMD.

Structural basis of selective TRPM7 inhibition by the anticancer agent CCT128930

TRP channels are implicated in various diseases, but high structural similarity between them makes selective pharmacological modulation challenging. Here, we study the molecular mechanism underlying specific inhibition of the TRPM7 channel, which is essential for cancer cell proliferation, by the anticancer agent CCT128930 (CCT). Using cryo-EM, functional analysis, and MD simulations, we show that CCT binds to a vanilloid-like (VL) site, stabilizing TRPM7 in the closed non-conducting state. Similar to other allosteric inhibitors of TRPM7, NS8593 and VER155008, binding of CCT is accompanied by displacement of a lipid that resides in the VL site in the apo condition. Moreover, we demonstrate the principal role of several residues in the VL site enabling CCT to inhibit TRPM7 without impacting the homologous TRPM6 channel. Hence, our results uncover the central role of the VL site for the selective interaction of TRPM7 with small molecules that can be explored in future drug design.

Cellular geometry and epithelial-mesenchymal plasticity intersect with PIEZO1 in breast cancer cells

Differences in shape can be a distinguishing feature between different cell types, but the shape of a cell can also be dynamic. Changes in cell shape are critical when cancer cells escape from the primary tumor and undergo major morphological changes that allow them to squeeze between endothelial cells, enter the vasculature, and metastasize to other areas of the body. A shift from rounded to spindly cellular geometry is a consequence of epithelial-mesenchymal plasticity, which is also associated with changes in gene expression, increased invasiveness, and therapeutic resistance. However, the consequences and functional impacts of cell shape changes and the mechanisms through which they occur are still poorly understood. Here, we demonstrate that altering the morphology of a cell produces a remodeling of calcium influx via the ion channel PIEZO1 and identify PIEZO1 as an inducer of features of epithelial-to-mesenchymal plasticity. Combining automated epifluorescence microscopy and a genetically encoded calcium indicator, we demonstrate that activation of the PIEZO1 force channel with the PIEZO1 agonist, YODA 1, induces features of epithelial-to-mesenchymal plasticity in breast cancer cells. These findings suggest that PIEZO1 is a critical point of convergence between shape-induced changes in cellular signaling and epithelial-mesenchymal plasticity in breast cancer cells.

Dysregulation of calcium homeostasis in cancer and its role in chemoresistance

Globally, cancer, as a major public health concern, poses a severe threat to people's well-being. Advanced and specialized therapies can now cure the majority of people with early-stage cancer. However, emerging resistance to traditional and novel chemotherapeutic drugs remains a serious issue in clinical medicine. Chemoresistance often leads to cancer recurrence, metastasis, and increased mortality, accounting for 90% of chemotherapy failures. Thus, it is important to understand the molecular mechanisms of chemoresistance and find novel therapeutic approaches for cancer treatment. Among the several factors responsible for chemoresistance, calcium (Ca2+) dysregulation plays a significant role in cancer progression and chemoresistance. Therefore, targeting this derailed Ca2+ signalling for cancer therapy has become an emerging research area. Of note, the Ca2+ signal and its proteins are a multifaceted and potent tool by which cells achieve specific outcomes. Depending on cell survival needs, Ca2+ is either upregulated or downregulated in both chemosensitive and chemoresistant cancer cells. Consequently, the appropriate treatment should be selected based on Ca2+ signalling dysregulation. This review discusses the role of Ca2+ in cancer cells and the targeting of Ca2+ channels, pumps, and exchangers. Furthermore, we have emphasised the role of Ca2+ in chemoresistance and therapeutic strategies. In conclusion, targeting Ca2+ signalling is a multifaceted process. Methods such as site-specific drug delivery, target-based drug-designing, and targeting two or more Ca2+ proteins simultaneously may be explored; however, further clinical studies are essential to validate Ca2+ blockers' anti-cancer efficacy.

ASIC1a contributes to the epithelial-mesenchymal transformation of breast cancer by activating the Ca2+ /β-catenin pathway

Breast cancer is the most common cancer in the world, with metastasis being one of the leading causes of death among patients. The acidic environment of breast cancer tissue promotes tumor cell invasion and migration by inducing epithelial-mesenchymal transformation (EMT) in tumor cells, but the exact mechanisms are not yet fully understood. This study investigated the expression of acid-sensitive ion channel 1a (ASIC1a) in breast cancer tissue samples and explored the mechanisms by which ASIC1a mediates the promotion of EMT in breast cancer cells in an acidic microenvironment through in vivo and in vitro experiments. The results showed that first, the expression of ASIC1a was significantly upregulated in breast cancer tissue and was correlated with the TNM (tumor node metastasis) staging of breast cancer. Furthermore, ASIC1a expression was higher in tumors with lymph node metastasis than in those without. Second, the acidic microenvironment promoted [Ca2+ ]i influx via ASIC1a activation and regulated the expression of β-catenin, Vimentin, and E-cadherin, thus promoting EMT in breast cancer cells. Inhibition of ASIC1a activation with PcTx-1 could suppress EMT in breast cancer cells. Finally, in vivo studies also showed that inhibition of ASIC1a could reduce breast cancer metastasis, invasion, and EMT. This study suggests that ASIC1a expression is associated with breast cancer staging and metastasis. Therefore, ASIC1a may become a new breast cancer biomarker, and the elucidation of the mechanism by which ASIC1a promotes EMT in breast cancer under acidic microenvironments provides evidence for the use of ASIC1a as a molecular target for breast cancer treatment.

Hypericum roeperianum bark extract suppresses breast cancer proliferation via induction of apoptosis, downregulation of PI3K/Akt/mTOR signaling cascade and reversal of EMT

ETHNOPHARMACOLOGICAL RELEVANCE

Hypericum roeperianum is a medicinal spice traditionally used in West Africa to treat female sterility, fungal infections, and cancer. It has previously been reported that H. roeperianum exhibits cytotoxic potential by reducing the viability of cancer cells involving multidrug-resistant phenotypes, but its underlying molecular mechanism remains unknown.

AIM OF THE STUDY

The mechanistic involvement of H. roeperianum methanolic crude extract (HRC) in attenuating breast cancer progression by exploring the effects on mitochondrial apoptosis and epithelial-mesenchymal transition (EMT) was investigated.

MATERIALS AND METHODS

In the present study, we examined the anticancer properties of HRC through MTT assay, colony formation, wound healing assay, spheroid formation, DNA fragmentation and flow cytometry for cell cycle arrest, apoptosis (Annexin V/PI staining) and mitochondrial membrane potential (MMP) (JC-1) detection. In addition, western blot analysis of various proteins and quantitative real time PCR of various genes involved in apoptosis, EMT and the PI3K/Akt/mToR signal transduction pathway were performed.

RESULTS

This study revealed that HRC treatment significantly decreased breast cancer cell viability, colony forming efficiency and reduced the ability of cell migration and spheroid formation. HRC also induced apoptosis in MDA-MB-231 and MCF-7 via promoting G0/G1 cell cycle arrest, disruption of mitochondrial membrane potential and induction of DNA damage. The crude extract induced apoptosis by activating the intrinsic pathway with a stronger effect that relies on the combined potency of associated molecular markers including Bax, Bad, Bcl-2, cytochrome C, caspase-9, and cleaved-PARP. It was also found that HRC regulates the PI3K/Akt/mToR pathway. In addition, HRC inhibited EMT by expressional alteration of Vimentin and E-cadherin, as well as the regulatory transcription factors such as Snail and Slug. The in vitro findings reflected similar mechanistic approach in 4T1 cell induced syngeneic mice model, indicating the reduction of tumor volume along with the significant expressional alteration of EMT and apoptotic markers.

CONCLUSION

Taken together the findings concluded that H. roeperianum is a potential source of cytotoxic phytochemicals that exhibit abortifacient effect on breast cancer, both in vitro and in vivo, thus could further be utilized in breast cancer therapy.

The Role of TRPM7 in Oncogenesis

This review summarizes the current understanding of the role of transient receptor potential melastatin-subfamily member 7 (TRPM7) channels in the pathophysiology of neoplastic diseases. The TRPM family represents the largest and most diverse group in the TRP superfamily. Its subtypes are expressed in virtually all human organs playing a central role in (patho)physiological events. The TRPM7 protein (along with TRPM2 and TRPM6) is unique in that it has kinase activity in addition to the channel function. Numerous studies demonstrate the role of TRPM7 chanzyme in tumorigenesis and in other tumor hallmarks such as proliferation, migration, invasion and metastasis. Here we provide an up-to-date overview about the possible role of TRMP7 in a broad range of malignancies such as tumors of the nervous system, head and neck cancers, malignant neoplasms of the upper gastrointestinal tract, colorectal carcinoma, lung cancer, neoplasms of the urinary system, breast cancer, malignant tumors of the female reproductive organs, prostate cancer and other neoplastic pathologies. Experimental data show that the increased expression and/or function of TRPM7 are observed in most malignant tumor types. Thus, TRPM7 chanzyme may be a promising target in tumor therapy.

The role of Ca2+-signaling in the regulation of epigenetic mechanisms

Epigenetic mechanisms regulate multiple cell functions like gene expression and chromatin conformation and stability, and its misregulation could lead to several diseases including cancer. Epigenetic drugs are currently under investigation in a broad range of diseases, but the cellular processes involved in regulating epigenetic mechanisms are not fully understood. Calcium (Ca2+) signaling regulates several cellular mechanisms such as proliferation, gene expression, and metabolism, among others. Moreover, Ca2+ signaling is also involved in diseases such as neurological disorders, cardiac, and cancer. Evidence indicates that Ca2+ signaling and epigenetics are involved in the same cellular functions, which suggests a possible interplay between both mechanisms. Ca2+-activated transcription factors regulate the recruitment of chromatin remodeling complexes into their target genes, and Ca2+-sensing proteins modulate their activity and intracellular localization. Thus, Ca2+ signaling is an important regulator of epigenetic mechanisms. Moreover, Ca2+ signaling activates epigenetic mechanisms that in turn regulate genes involved in Ca2+ signaling, suggesting possible feedback between both mechanisms. The understanding of how epigenetics are regulated could lead to developing better therapeutical approaches.

Searching for Essential Genes and Targeted Drugs Common to Breast Cancer and Osteoarthritis

BACKGROUND

It is documented that osteoarthritis can promote the progression of breast cancer (BC).

OBJECTIVE

This study aims to search for the essential genes associated with breast cancer (BC) and osteoarthritis (OA), explore the relationship between epithelial-mesenchymal transition (EMT)- related genes and the two diseases, and identify the candidate drugs.

METHODS

The genes related to both BC and OA were determined by text mining. Protein-protein Interaction (PPI) analysis was carried out, and as a result, the exported genes were found to be related to EMT. PPI and the correlation of mRNA of these genes were also analyzed. Different kinds of enrichment analyses were performed on these genes. A prognostic analysis was performed on these genes for examining their expression levels at different pathological stages, in different tissues, and in different immune cells. Drug-gene interaction database was employed for potential drug discovery.

RESULTS

A total number of 1422 genes were identified as common to BC and OA and 58 genes were found to be related to EMT. We found that HDAC2 and TGFBR1 were significantly poor in overall survival. High expression of HDAC2 plays a vital role in the increase of pathological stages. Four immune cells might play a role in this process. Fifty-seven drugs were identified that could potentially have therapeutic effects.

CONCLUSION

EMT may be one of the mechanisms by which OA affects BC. Using the drugs can have potential therapeutic effects, which may benefit patients with both diseases and broaden the indications for drug use.

Simultaneous Proximity DNAzyme-Activated Duplexed Protein-Specific Glycosylation Imaging on Cell Surface via Bioorthogonal Chemistry

Due to the scarcity of strategies to evaluate the multiple subtype monosaccharides in one specific protein simultaneously within a single assay, understanding the glycosylation mechanisms and revealing their roles in disease development become extremely challenging. Herein, a strategy of proximity DNAzyme-activated fluorescence imaging of multiplex saccharides in a protein on the cell surface via bio-orthogonal chemistry is reported. The multichannel proximity DNAzyme-activated fluorescence recovery enabled the highly selective and effective imaging analysis of multiplexed protein-specific glycosylation in situ and has been demonstrated. This strategy is successfully applied to visualize the sialylation and fucosylation in four specific proteins on different cell lines and evaluate the variations of protein-specific glycosylation in response to the alterations of the cellular physiological status. More importantly, the quantitative tracking of the terminal sialyation and fucosylation changes at the single-protein level is realized by assigning the target protein as the native reference, which has the potential to be a versatile platform for glycobiology research and clinical diagnosis.

Light-Induced Nanoscale Deformation in Azobenzene Thin Film Triggers Rapid Intracellular Ca2+ Increase via Mechanosensitive Cation Channels

Epithelial cells are in continuous dynamic biochemical and physical interaction with their extracellular environment. Ultimately, this interplay guides fundamental physiological processes. In these interactions, cells generate fast local and global transients of Ca2+ ions, which act as key intracellular messengers. However, the mechanical triggers initiating these responses have remained unclear. Light-responsive materials offer intriguing possibilities to dynamically modify the physical niche of the cells. Here, a light-sensitive azobenzene-based glassy material that can be micropatterned with visible light to undergo spatiotemporally controlled deformations is used. Real-time monitoring of consequential rapid intracellular Ca2+ signals reveals that the mechanosensitive cation channel Piezo1 has a major role in generating the Ca2+ transients after nanoscale mechanical deformation of the cell culture substrate. Furthermore, the studies indicate that Piezo1 preferably responds to shear deformation at the cell-material interphase rather than to absolute topographical change of the substrate. Finally, the experimentally verified computational model suggests that Na+ entering alongside Ca2+ through the mechanosensitive cation channels modulates the duration of Ca2+ transients, influencing differently the directly stimulated cells and their neighbors. This highlights the complexity of mechanical signaling in multicellular systems. These results give mechanistic understanding on how cells respond to rapid nanoscale material dynamics and deformations.

Capsaicinoids and Their Effects on Cancer: The "Double-Edged Sword" Postulate from the Molecular Scale

Capsaicinoids are a unique chemical species resulting from a particular biosynthesis pathway of hot chilies (Capsicum spp.) that gives rise to 22 analogous compounds, all of which are TRPV1 agonists and, therefore, responsible for the pungency of Capsicum fruits. In addition to their human consumption, numerous ethnopharmacological uses of chili have emerged throughout history. Today, more than 25 years of basic research accredit a multifaceted bioactivity mainly to capsaicin, highlighting its antitumor properties mediated by cytotoxicity and immunological adjuvancy against at least 74 varieties of cancer, while non-cancer cells tend to have greater tolerance. However, despite the progress regarding the understanding of its mechanisms of action, the benefit and safety of capsaicinoids' pharmacological use remain subjects of discussion, since CAP also promotes epithelial-mesenchymal transition, in an ambivalence that has been referred to as "the double-edge sword". Here, we update the comparative discussion of relevant reports about capsaicinoids' bioactivity in a plethora of experimental models of cancer in terms of selectivity, efficacy, and safety. Through an integration of the underlying mechanisms, as well as inherent aspects of cancer biology, we propose mechanistic models regarding the dichotomy of their effects. Finally, we discuss a selection of in vivo evidence concerning capsaicinoids' immunomodulatory properties against cancer.

Cleft palate and minor metabolic disturbances in a mouse global Arl15 gene knockout

ARL15, a small GTPase protein, was linked to metabolic traits in association studies. We aimed to test the Arl15 gene as a functional candidate for metabolic traits in the mouse. CRISPR/Cas9 germline knockout (KO) of Arl15 showed that homozygotes were postnatal lethal and exhibited a complete cleft palate (CP). Also, decreased cell migration was observed from Arl15 KO mouse embryonic fibroblasts (MEFs). Metabolic phenotyping of heterozygotes showed that females had reduced fat mass on a chow diet from 14 weeks of age. Mild body composition phenotypes were also observed in heterozygous mice on a high-fat diet (HFD)/low-fat diet (LFD). Females on a HFD showed reduced body weight, gonadal fat depot weight and brown adipose tissue (BAT) weight. In contrast, in the LFD group, females showed increased bone mineral density (BMD), while males showed a trend toward reduced BMD. Clinical biochemistry analysis of plasma on HFD showed transient lower adiponectin at 20 weeks of age in females. Urinary and plasma Mg2+ concentrations were not significantly different. Our phenotyping data showed that Arl15 is essential for craniofacial development. Adult metabolic phenotyping revealed potential roles in brown adipose tissue and bone development.

Regulation of Epithelial-Mesenchymal Transitions by Alternative Splicing: Potential New Area for Cancer Therapeutics

The epithelial-mesenchymal transition (EMT) is a complicated biological process in which cells with epithelial phenotype are transformed into mesenchymal cells with loss of cell polarity and cell-cell adhesion and gain of the ability to migrate. EMT and the reverse mesenchymal-epithelial transitions (METs) are present during cancer progression and metastasis. Using the dynamic switch between EMT and MET, tumour cells can migrate to neighbouring organs or metastasize in the distance and develop resistance to traditional chemotherapy and targeted drug treatments. Growing evidence shows that reversing or inhibiting EMT may be an advantageous approach for suppressing the migration of tumour cells or distant metastasis. Among different levels of modulation of EMT, alternative splicing (AS) plays an important role. An in-depth understanding of the role of AS and EMT in cancer is not only helpful to better understand the occurrence and regulation of EMT in cancer progression, but also may provide new therapeutic strategies. This review will present and discuss various splice variants and splicing factors that have been shown to play a crucial role in EMT.

Mechanosensitive Ion Channels: Their Physiological Importance and Potential Key Role in Cancer

Mechanosensitive ion channels comprise a broad group of proteins that sense mechanical extracellular and intracellular changes, translating them into cation influx to adapt and respond to these physical cues. All cells in the organism are mechanosensitive, and these physical cues have proven to have an important role in regulating proliferation, cell fate and differentiation, migration and cellular stress, among other processes. Indeed, the mechanical properties of the extracellular matrix in cancer change drastically due to high cell proliferation and modification of extracellular protein secretion, suggesting an important contribution to tumor cell regulation. In this review, we describe the physiological significance of mechanosensitive ion channels, emphasizing their role in cancer and immunity, and providing compelling proof of the importance of continuing to explore their potential as new therapeutic targets in cancer research.

Identification of an endoplasmic reticulum stress-related prognostic risk model with excellent prognostic and clinical value in oral squamous cell carcinoma

BACKGROUND

Recently, endoplasmic reticulum stress related gene (ERS) markers have performed very well in predicting the prognosis of tumor patients.

METHODS

The differentially expressed genes in Oral squamous cell carcinoma (OSCC) were obtained from TCGA and GTEx database. Three prognosis-related and differentially expressed ERSs were screened out by Least Absolute Selection and Shrinkage Operator (Lasso) regression to construct a prognostic risk model. Receiver Operating Characteristic Curve (ROC), riskplots and survival curves were used to verify the model's accuracy in predicting prognosis. Multi-omics analysis of immune infiltration, gene mutation, and stem cell characteristics were performed to explore the possible mechanism of OSCC. Finally, we discussed the model's clinical application value from the perspective of drug sensitivity.

RESULTS

Three genes used in the model (IBSP, RDM1, RBP4) were identified as prognostic risk factors. Bioinformatics analysis, tissue and cell experiments have fully verified the abnormal expression of these three genes in OSCC. Multiple validation methods and internal and external datasets confirmed the model's excellent performance in predicting and discriminating prognosis. Cox regression analysis identified risk score as an independent predictor of prognosis. Multi-omics analysis found strong correlations between risk scores and immune cells, cell stemness index, and tumor mutational burden (TMB). It was also observed that the risk score was closely related to the half maximal inhibitory concentration of docetaxel, gefitinib and erlotinib. The excellent performance of the nomogram has been verified by various means.

CONCLUSION

A prognostic model with high clinical application value was constructed. Immune cells, cellular stemness, and TMB may be involved in the progression of OSCC.

Calcium signal modulation in breast cancer aggressiveness

Breast cancer (BC) is the second most common cancer and cause of death in women. The aggressive subtypes including triple negative types (TNBCs) show a resistance to chemotherapy, impaired immune system, and a worse prognosis. From a histological point of view, TNBCs are deficient in oestrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 (HER2⁺) expression. Many studies reported an alteration in the expression of calcium channels, calcium binding proteins and pumps in BC that promote proliferation, survival, resistance to chemotherapy, and metastasis. Moreover, Ca²⁺ signal remodeling and calcium transporters expression have been associated to TNBCs and HER2⁺ BC subtypes. This review provides insight into the underlying alteration of the expression of calcium-permeable channels, pumps, and calcium dependent proteins and how this alteration plays an important role in promoting metastasis, metabolic switching, inflammation, and escape to chemotherapy treatment and immune surveillance in aggressive BC including TNBCs models and highly metastatic BC tumors.

Intersection between calcium signalling and epithelial-mesenchymal plasticity in the context of cancer

Epithelial-mesenchymal transition (EMT) is a form of cellular phenotypic plasticity and is considered a crucial step in the progression of many cancers. The calcium ion (Ca²⁺) acts as a ubiquitous second messenger and is implicated in many cellular processes, including cell death, migration, invasion and more recently EMT. Throughout this review, the complex interplay between Ca²⁺ signalling and EMT will be explored. An overview of the Ca²⁺ pathways that are remodelled as a consequence of EMT is provided and the role of Ca²⁺ signalling in regulating EMT and its significance is considered. Ca²⁺ signalling pathways may represent a therapeutic opportunity to regulate EMT. However, as will be described in this review, the complexity of these signalling pathways represents significant challenges that must be considered if Ca²⁺ signalling is to be manipulated with the aim of therapeutic intervention in cancer.

Sodium regulates PLC and IP3 R-mediated calcium signaling in invasive breast cancer cells

Intracellular Ca2+ signaling and Na+ homeostasis are inextricably linked via ion channels and co-transporters, with alterations in the concentration of one ion having profound effects on the other. Evidence indicates that intracellular Na+ concentration ([Na+ ]i ) is elevated in breast tumors, and that aberrant Ca2+ signaling regulates numerous key cancer hallmark processes. The present study therefore aimed to determine the effects of Na+ depletion on intracellular Ca2+ handling in metastatic breast cancer cell lines. The relationship between Na+ and Ca2+ was probed using fura-2 and SBFI fluorescence imaging and replacement of extracellular Na+ with equimolar N-methyl-D-glucamine (0Na+ /NMDG) or choline chloride (0Na+ /ChoCl). In triple-negative MDA-MB-231 and MDA-MB-468 cells and Her2+ SKBR3 cells, but not ER+ MCF-7 cells, 0Na+ /NMDG and 0Na+ /ChoCl resulted in a slow, sustained depletion in [Na+ ]i that was accompanied by a rapid and sustained increase in intracellular Ca2+ concentration ([Ca2+ ]i ). Application of La3+ in nominal Ca2+ -free conditions had no effect on this response, ruling out reverse-mode NCX activity and Ca2+ entry channels. Moreover, the Na+ -linked [Ca2+ ]i increase was independent of membrane potential hyperpolarization (NS-1619), but was inhibited by pharmacological blockade of IP3 receptors (2-APB), phospholipase C (PLC, U73122) or following depletion of endoplasmic reticulum Ca2+ stores (cyclopiazonic acid). Thus, Na+ is linked to PLC/IP3 -mediated activation of endoplasmic reticulum Ca2+ release in metastatic breast cancer cells and this may have an important role in breast tumors where [Na+ ]i is perturbed.

Involvement of TRPM7 in Alcohol-Induced Damage of the Blood-Brain Barrier in the Presence of HIV Viral Proteins

Ethanol (EtOH) exerts its effects through various protein targets, including transient receptor potential melastatin 7 (TRPM7) channels, which play an essential role in cellular homeostasis. We demonstrated that TRPM7 is expressed in rat brain microvascular endothelial cells (rBMVECs), the major cellular component of the blood-brain barrier (BBB). Heavy alcohol drinking is often associated with HIV infection, however mechanisms underlying alcohol-induced BBB damage and HIV proteins, are not fully understood. We utilized the HIV-1 transgenic (HIV-1Tg) rat to mimic HIV-1 patients on combination anti-retroviral therapy (cART) and demonstrated TRPM7 expression in rBMVECs wass lower in adolescent HIV-1Tg rats compared to control animals, however control and HIV-1Tg rats expressed similar levels at 9 weeks, indicating persistent presence of HIV-1 proteins delayed TRPM7 expression. Binge exposure to EtOH (binge EtOH) decreased TRPM7 expression in control rBMVECs in a concentration-dependent manner, and abolished TRPM7 expression in HIV-1Tg rats. In human BMVECs (hBMVECs), TRPM7 expression was downregulated after treatment with EtOH, HIV-1 proteins, and in combination. Next, we constructed in vitro BBB models using BMVECs and found TRPM7 antagonists enhanced EtOH-mediated BBB integrity changes. Our study demonstrated alcohol decreased TRPM7 expression, whereby TRPM7 could be involved in the mechanisms underlying BBB alcohol-induced damage in HIV-1 patients on cART.

Breast cancer heterogeneity and its implication in personalized precision therapy

Breast cancer heterogeneity determines cancer progression, treatment effects, and prognosis. However, the precise mechanism for this heterogeneity remains unknown owing to its complexity. Here, we summarize the origins of breast cancer heterogeneity and its influence on disease progression, recurrence, and therapeutic resistance. We review the possible mechanisms of heterogeneity and the research methods used to analyze it. We also highlight the importance of cell interactions for the origins of breast cancer heterogeneity, which can be further categorized into cooperative and competitive interactions. Finally, we provide new insights into precise individual treatments based on heterogeneity.

A pan-cancer-bioinformatic-based literature review of TRPM7 in cancers

TRPM7, a divalent cation-selective channel with kinase domains, has been widely reported to potentially affect cancers. In this study, we conducted multiple bioinformatic analyses based on open databases and reviewed articles that provided evidence for the effects of TRPM7 on cancers. The purposes of this paper are 1) to provide a pan-cancer overview of TRPM7 in cancers; 2) to summarize evidence of TRPM7 effects on cancers; 3) to identify potential future studies of TRPM7 in cancer. Bioinformatics analysis revealed that no cancer-related TRPM7 mutation was found. TRPM7 is aberrantly expressed in most cancer types but the cancer-noncancer expression pattern varies across cancer types. TRPM7 was not associated with survival, TMB, or cancer stemness in most cancer types. TRPM7 affected drug sensitivity and tumor immunity in some cancer types. The in vitro evidence, preclinical in vivo evidence, and clinical evidence for TRPM7 effects on cancers as well as TRPM7 kinase substrate and TRPM7-targeting drugs associated with cancers were summarized to facilitate comparison. We matched the bioinformatics evidence to literature evidence, thereby unveiling potential avenues for future investigation of TRPM7 in cancers. We believe that this paper will help orient research toward important and relevant aspects of the role of TRPM7 in cancers.

Chemokine/GPCR Signaling-Mediated EMT in Cancer Metastasis

Metastasis, the chief cause of cancer-related deaths, is associated with epithelial-mesenchymal transition (EMT). In the tumor microenvironment, EMT can be triggered by chemokine/G-protein-coupled receptor (GPCR) signaling, which is closely associated with tumor progression. However, the functional links between chemokine/GPCR signaling-mediated EMT and metastasis remain unclear. Herein, we summarized the mechanisms of chemokine/GPCR signaling-mediated EMT with an insight into facilitating metastasis and clarified the role of chemokine in the local invasion, intravasation, circulation, extravasation, and colonization, respectively. Moreover, several potential pathways that might contribute to EMT based on the latest studies on GPCR signaling were proposed, including signaling mediated by G protein, β-arrestin, intracellular, dimerization activation, and transactivation. However, there is still limited evidence to support the EMT programme functional contribution to metastasis, which keeps a key question still open whether we should target EMT programme of cancer cells. Answers to that question might help develop an anticancer strategy or guide new directions for anticancer metastasis therapy.

A ROS/Akt/NF-κB Signaling Cascade Mediates Epidermal Growth Factor-Induced Epithelial-Mesenchymal Transition and Invasion in Human Breast Cancer Cells

BACKGROUND

As one of the most widely used anti-diabetic drugs for type II diabetes, metformin has been shown to exhibit anti-cancer activity in recent years. Epidermal growth factor (EGF) and its receptor, EGFR, play important roles in cancer metastasis in various tumors, including breast cancer. Epithelial-mesenchymal transition (EMT) is a critical process for cancer invasion and metastasis. In this study, we use EGF as a metastatic inducer to investigate the effect of metformin on cancer cell migration, invasion and EMT.

METHODS

Human breast cancer MCF-7 cells were exposed to EGF with or without metformin or N-acetyl cysteine (NAC). The effects of metformin on breast cancer cell proliferation were analyzed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. The production of reactive oxygen species (ROS) was tested using 2,7-dichlorodihydrofluorecein diacetate (DCFH-DA). The migratory and invasive abilities of tumor cells were analyzed using wound healing assay and transwell invasion assay, respectively. The expressions of E-cadherin, N-cadherin and Snail were tested using real-time quantitative polymerase chain reaction (qRT-PCR) and western blotting at mRNA and protein levels. The activation of protein kinase B (Akt) and nuclear factor kappa B (NF-κB) were measured by western blotting.

RESULTS

Our results showed that metformin inhibited breast cancer cell proliferation in a dose-dependent manner with or without EGF. EGF-induced alterations in cell morphology that are characteristic of EMT were reversed by metformin. Metformin also inhibited the EGF-modulated expression of E-cadherin, N-cadherin and Snail and further suppressed cell invasion and migration. In addition, metformin suppressed EGF-induced phosphorylation of Akt and NF-κB. ROS is involved in EGF-induced cancer invasion and activation of phosphatidylinositol 3-kinase (PI3K)/Akt/NF-κB pathway.

CONCLUSION

Taken together, these data indicate that metformin suppresses EGF-induced breast cancer cell migration, invasion and EMT through the inhibition of the PI3K/Akt/NF-κB pathway. These results provide a novel mechanism to explain the role of metformin as a potent anti-metastatic agent in breast cancer cells.

SNAI1-dependent upregulation of CD73 increases extracellular adenosine release to mediate immune suppression in TNBC

Triple-negative subtype of breast cancer (TNBC) is hallmarked by frequent disease relapse and shows highest mortality rate. Although PD-1/PD-L1 immune checkpoint blockades have recently shown promising clinical benefits, the overall response rate remains largely insufficient. Hence, alternative therapeutic approaches are warranted. Given the immunosuppressive properties of CD73-mediated adenosine release, CD73 blocking approaches are emerging as attractive strategies in cancer immunotherapy. Understanding the precise mechanism regulating the expression of CD73 is required to develop effective anti-CD73-based therapy. Our previous observations demonstrate that the transcription factors driving epithelial-to-mesenchymal transition (EMT-TF) can regulate the expression of several inhibitory immune checkpoints. Here we analyzed the role of the EMT-TF SNAI1 in the regulation of CD73 in TNBC cells. We found that doxycycline-driven SNAI1 expression in the epithelial -like TNBC cell line MDA-MB-468 results in CD73 upregulation by direct binding to the CD73 proximal promoter. SNAI1-dependent upregulation of CD73 leads to increased production and release of extracellular adenosine by TNBC cells and contributes to the enhancement of TNBC immunosuppressive properties. Our data are validated in TNBC samples by showing a positive correlation between the mRNA expression of CD73 and SNAI1. Overall, our results reveal a new CD73 regulation mechanism in TNBC that participates in TNBC-mediated immunosuppression and paves the way for developing new treatment opportunities for CD73-positive TNBC.

Calcium influx through TRPV4 channels involve in hyperosmotic stress-induced epithelial-mesenchymal transition in tubular epithelial cells

The epithelial-mesenchymal transition (EMT) is a biological process that occurs in the pathogenesis of kidney diseases in which injured tubular epithelial cells transform into myofibroblasts. We previously showed that mannitol-mediated hyperosmotic stress induces EMT of tubular epithelial cells. Although Ca²⁺ signaling is essential for the induction of EMT in tubular epithelial cells, the role of specific calcium channels is unknown. In this study, we assessed the transient receptor potential vanilloid 4 (TRPV4)-mediated Ca²⁺ influx in the hyperosmolarity-induced EMT. The Fluo-4 assay was used to examine the effect of hyperosmotic stress on the intracellular Ca²⁺ level of normal rat kidney (NRK)-52E cells. Expression of a mesenchymal marker α-smooth muscle actin (α-SMA) and an epithelial marker E-cadherin was also observed by fluorescence microscopy. The hyperosmotic stress caused a transient increase in intracellular Ca²⁺ concentration as well as a decrease in E-cadherin and an increase in α-SMA expressions in tubular epithelial cells, indicating the induction of EMT. A TRPV4 channel antagonist inhibited hyperosmotic stress-induced Ca²⁺ influx and the EMT, whereas, a TRPV4 channel agonist increased Ca²⁺ influx and EMT induction in tubular epithelial cells without the hyperosmotic stress. These findings suggest that Ca²⁺ influx through TRPV4 channels contributes to the hyperosmotic stress-induced EMT of tubular epithelial cells.

Glycosphingolipids are mediators of cancer plasticity through independent signaling pathways

The molecular repertoire promoting cancer cell plasticity is not fully elucidated. Here, we propose that glycosphingolipids (GSLs), specifically the globo and ganglio series, correlate and promote the transition between epithelial and mesenchymal cells. The epithelial character of ovarian cancer remains stable throughout disease progression, and spatial glycosphingolipidomics reveals elevated globosides in the tumor compartment compared with the ganglioside-rich stroma. CRISPR-Cas9 knockin mediated truncation of endogenous E-cadherin induces epithelial-to-mesenchymal transition (EMT) and decreases globosides. The transcriptomics analysis identifies the ganglioside-synthesizing enzyme ST8SIA1 to be consistently elevated in mesenchymal-like samples, predicting poor outcome. Subsequent deletion of ST8SIA1 induces epithelial cell features through mTOR^S2448 phosphorylation, whereas loss of globosides in ΔA4GALT cells, resulting in EMT, is accompanied by increased ERK^Y202/T204 and AKT^S124. The GSL composition dynamics corroborate cancer cell plasticity, and further evidence suggests that mesenchymal cells are maintained through ganglioside-dependent, calcium-mediated mechanisms.

Combinatorial delivery of CPI444 and vatalanib loaded on PEGylated graphene oxide as an effective nanoformulation to target glioblastoma multiforme: In vitro evaluation

Glioblastoma multiforme (GBM) is known as the primary malignant and most devastating form of tumor found in the central nervous system of the adult population. The active pharmaceutical component in current chemotherapy regimens is mostly hydrophobic and poorly water-soluble, which hampers clinical implications. Nanodrug formulations using nanocarriers loaded with such drugs assisted in water dispersibility, improved cellular permeability, and drug efficacy at a low dose, thus adding to the overall practical value. Here, we successfully developed a water-dispersible and biocompatible nanocargo (GO-PEG) based on covalently modified graphene oxide (GO) with a 6-armed poly(ethylene glycol) amine dendrimer for effective loading of the two hydrophobic anticancer drug molecules, CPI444 and vatalanib. These drug molecules target adenosine receptor (A2AR), vascular endothelial growth factor receptor (VEGFR), platelet-derived growth factor receptor (PDGFR), and type III stem cell receptor tyrosine kinase (c-KIT), which plays a crucial role in cancers. The effective cellular delivery of the drugs when loaded on GO-PEG is attributed to the increased permeability of the drug-nanoconjugate formulation. We observed that this combinatorial drug treatment with nanocargo resulted in a significant reduction in the overall cell survival as supported by reduced calcium levels and stem cell markers such as Oct4 and Nanog, which are two of the prime factors for GBM stem cell proliferation. Furthermore, reduced expression of CD24 upon treatment with nanoformulation impeded cellular migration. Cellular assays confirmed inhibition of cell proliferation, migration, and angiogenic potential of GBM treated with GO-PEG–Drug conjugates. Ultimately, GBM U87 cells assumed programmed cell death at a very low concentration due to nanocarrier-mediated drug delivery along with the chosen combination of drugs. Together, this study demonstrated the advantage of GO-PEG mediated combined delivery of CPI444 and vatalanib drugs with increased permeability, a three-pronged combinatorial strategy toward effective GBM treatment.

Potential of the TRPM7 channel as a novel therapeutic target for pulmonary arterial hypertension

Pulmonary arterial hypertension (PAH) is an intractable vascular disease characterized by a progressive increase in pulmonary vascular resistance caused by pulmonary vascular remodeling, which ultimately leads to right-sided heart failure. PAH remains incurable, despite the development of PAH-targeted therapeutics centered on pulmonary artery relaxants. It is necessary to identify the target molecules that contribute to pulmonary artery remodeling. Transient receptor potential (TRP) channels have been suggested to modulate pulmonary artery remodeling. Our study focused on the transient receptor potential ion channel subfamily M, member 7, or the TRPM7 channel, which modulates endothelial-to-mesenchymal transition and smooth muscle proliferation in the pulmonary artery. In this review, we summarize the role and expression profile of TRPM7 channels in PAH progression and discuss TRPM7 channels as possible therapeutic targets. In addition, we discuss the therapeutic effect of a Chinese herbal medicine, Ophiocordyceps sinensis (OCS), on PAH progression, which partly involves TRPM7 inhibition.

Insights on possible interplay between epithelial-mesenchymal transition and T-type voltage gated calcium channels genes in metastatic breast carcinoma

Breast cancer (BC) is the most common life-threatening malignancy amongst women with high incidence worldwide. In Egypt, it is the most known malignancy amongst females. Epithelial-mesenchymal transition (EMT) participates in breast tumors’ invasiveness, and metastasis, but the process is poorly understood. The involvement of voltage-gated calcium channels signaling in EMT has not yet been fully explored. Therefore, the aim of this study was to investigate the possible role of T-type calcium channels in metastasis and EMT among breast cancer patients. The study was carried out on 48 female breast cancer patients who were divided into two groups; metastatic and non-metastatic. qRT-PCR was employed to measure the expression of EMT marker genes (N- cadherin, E-cadherin, Snail, Vimentin and T-type VGCCs genes (CACNA1G, CACNA1H, and CACNA1I). The results of the present study revealed differential expression of the EMT marker genes in blood and tissue of non-metastatic and metastatic breast cancer patients, with a clear tendency for the mesenchymal markers to be significantly elevated in metastatic patients as well as malignant tissues taken from non-metastatic patients as compared to their paired tumor adjacent normal (TAN) tissue. Both CACNA1H and CACNA1I (T-type VGCCs oncogenes) were significantly elevated in blood of metastatic patients when compared to non-metastatic ones. In contrast, CACNA1G (tumor suppressor) exhibited a significant decrease in metastatic patients. The strong correlation between the expression of T-type VGCCs and mesenchymal marker genes in metastatic breast cancer patients casts light on the role of T-type VGCCs in metastasis and their involved in tumor invasiveness.

Stanniocalcin 2 drives malignant transformation of human glioblastoma cells by targeting SNAI2 and Matrix Metalloproteinases

Glioblastoma multiforme (GBM) is the most malignant brain tumor and is refractory to conventional therapies. Although previous studies have proposed that the interaction between gene mutations and the external environment leads to the occurrence of GBM, the pathogenesis of GBM is still unclear and much remains to be studied. Herein, we show an association between human glycoprotein stanniocalcin-2 (STC2) and aggressive GBM progression, and demonstrate the underlying mechanism. Elevated STC2 expression and secretion greatly increase GBM cell growth and invasive phenotypes. Mechanistically, both, conditioned media (CM) containing STC2 and recombinant STC2, can induce the transformation of GBM cells into more malignant phenotypes by upregulating the expression of the epithelial-mesenchymal transition transcription factor, snail family transcription repressor 2 (SNAI2) as well as matrix metalloproteinases (MMPs). Moreover, we further demonstrate that the oncogenic function of STC2 in GBM is mediated through the MAPK signaling pathway. Collectively, these results identify the mechanism of STC2 targeting SNAI2 and MMPs through the MAPK pathway in GBM, and provide insights into a potential therapeutic strategy for GBM.

Aberrant calcium signalling downstream of mutations in TP53 and the PI3K/AKT pathway genes promotes disease progression and therapy resistance in triple negative breast cancer

Triple-negative breast cancer (TNBC) is characterized as an aggressive form of breast cancer (BC) associated with poor patient outcomes. For the majority of patients, there is a lack of approved targeted therapies. Therefore, chemotherapy remains a key treatment option for these patients, but significant issues around acquired resistance limit its efficacy. Thus, TNBC has an unmet need for new targeted personalized medicine approaches. Calcium (Ca²⁺) is a ubiquitous second messenger that is known to control a range of key cellular processes by mediating signalling transduction and gene transcription. Changes in Ca²⁺ through altered calcium channel expression or activity are known to promote tumorigenesis and treatment resistance in a range of cancers including BC. Emerging evidence shows that this is mediated by Ca²⁺ modulation, supporting the function of tumour suppressor genes (TSGs) and oncogenes. This review provides insight into the underlying alterations in calcium signalling and how it plays a key role in promoting disease progression and therapy resistance in TNBC which harbours mutations in tumour protein p53 (TP53) and the PI3K/AKT pathway.

Vibration, a treatment for migraine, linked to calpain driven changes in actin cytoskeleton

Understanding how a human cell reacts to external physical stimuli is essential to understanding why vibration can elicit localized pain reduction. Stimulation of epithelial cells with external vibration forces has been shown to change cell shape, particularly in regards to structures involved in non-muscle cell motility. We hypothesized that epithelial cells respond to vibration transduction by altering proteins involved in remodeling cytoskeleton. Epithelial cells were exposed to vibration and assessed by microscopy, cytoskeletal staining, immunoblotting and quantitative RT-PCR. Here, we report that epithelial cell lines exposed to 15 minutes of vibration retract filopodia and concentrate actin at the periphery of the cell. In particular, we show an increased expression of the calcium-dependent, cysteine protease, calpain. The discovery that cell transitions are induced by limited exposure to natural forces, such as vibration, provides a foundation to explain how vibrational treatment helps migraine patients.

Bioelectric Dysregulation in Cancer Initiation, Promotion, and Progression

Cancer is primarily a disease of dysregulation – both at the genetic level and at the tissue organization level. One way that tissue organization is dysregulated is by changes in the bioelectric regulation of cell signaling pathways. At the basis of bioelectricity lies the cellular membrane potential or V_mem, an intrinsic property associated with any cell. The bioelectric state of cancer cells is different from that of healthy cells, causing a disruption in the cellular signaling pathways. This disruption or dysregulation affects all three processes of carcinogenesis – initiation, promotion, and progression. Another mechanism that facilitates the homeostasis of cell signaling pathways is the production of extracellular vesicles (EVs) by cells. EVs also play a role in carcinogenesis by mediating cellular communication within the tumor microenvironment (TME). Furthermore, the production and release of EVs is altered in cancer. To this end, the change in cell electrical state and in EV production are responsible for the bioelectric dysregulation which occurs during cancer. This paper reviews the bioelectric dysregulation associated with carcinogenesis, including the TME and metastasis. We also look at the major ion channels associated with cancer and current technologies and tools used to detect and manipulate bioelectric properties of cells.

In Silico Analysis of Ion Channels and Their Correlation with Epithelial to Mesenchymal Transition in Breast Cancer

Simple Summary

Breast cancer involves changes in the healthy cells of the breast resulting in rapid and abnormal division of cells that later spread to other parts of the body through the process of metastasis, which involves epithelial mesenchymal transition (EMT). Ion channels play a significant role in the switch from epithelial to mesenchymal transition through their contributions to cellular motility, cell volume regulation and cell cycle progression. Comprehensive computational analyses were performed to understand the role of ion channels in tumor/metastatic samples of breast cancer and their correlation with EMT.

Abstract

Uncontrolled growth of breast cells due to altered gene expression is a key feature of breast cancer. Alterations in the expression of ion channels lead to variations in cellular activities, thus contributing to attributes of cancer hallmarks. Changes in the expression levels of ion channels were observed as a consequence of EMT. Additionally, ion channels were reported in the activation of EMT and maintenance of a mesenchymal phenotype. Here, to identify altered ion channels in breast cancer patients, differential gene expression and weighted gene co-expression network analyses were performed using transcriptomic data. Protein–protein interactions network analysis was carried out to determine the ion channels interacting with hub EMT-related genes in breast cancer. Thirty-two ion channels were found interacting with twenty-six hub EMT-related genes. The identified ion channels were further correlated with EMT scores, indicating mesenchymal phenotype. Further, the pathway map was generated to represent a snapshot of deregulated cellular processes by altered ion channels and EMT-related genes. Kaplan–Meier five-year survival analysis and Cox regressions indicated the expression of CACNA1B, ANO6, TRPV3, VDAC1 and VDAC2 to be potentially associated with poor survival. Deregulated ion channels correlate with EMT-related genes and have a crucial role in breast cancer-associated tumorigenesis. Most likely, they are potential candidates for the determination of prognosis in patients with breast cancer.

Focusing on Mechanoregulation Axis in Fibrosis: Sensing, Transduction and Effecting

Fibrosis, a pathologic process featured by the excessive deposition of connective tissue components, can affect virtually every organ and has no satisfactory therapy yet. Fibrotic diseases are often associated with organ dysfunction which leads to high morbidity and mortality. Biomechanical stmuli and the corresponding cellular response havebeen identified in fibrogenesis, as the fibrotic remodeling could be seen as the incapacity to reestablish mechanical homeostasis: along with extracellular matrix accumulating, the physical property became more “stiff” and could in turn induce fibrosis. In this review, we provide a comprehensive overview of mechanoregulation in fibrosis, from initialing cellular mechanosensing to intracellular mechanotransduction and processing, and ends up in mechanoeffecting. Our contents are not limited to the cellular mechanism, but further expand to the disorders involved and current clinical trials, providing an insight into the disease and hopefully inspiring new approaches for the treatment of tissue fibrosis.

Ca2+ Transportome and the Interorganelle Communication in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is a type of liver cancer with a poor prognosis for survival given the complications it bears on the patient. Though damages to the liver are acknowledged prodromic factors, the precise molecular aetiology remains ill-defined. However, many genes coding for proteins involved in calcium (Ca²⁺) homeostasis emerge as either mutated or deregulated. Ca²⁺ is a versatile signalling messenger that regulates functions that prime and drive oncogenesis, favouring metabolic reprogramming and gene expression. Ca²⁺ is present in cell compartments, between which it is trafficked through a network of transporters and exchangers, known as the Ca²⁺ transportome. The latter regulates and controls Ca²⁺ dynamics and tonicity. In HCC, the deregulation of the Ca²⁺ transportome contributes to tumorigenesis, the formation of metastasizing cells, and evasion of cell death. In this review, we reflect on these aspects by summarizing the current knowledge of the Ca²⁺ transportome and overviewing its composition in the plasma membrane, endoplasmic reticulum, and the mitochondria.

Towards an integrative understanding of cancer mechanobiology: calcium, YAP, and microRNA under biophysical forces

An increasing number of studies have demonstrated the significant roles of the interplay between microenvironmental mechanics in tissues and biochemical-genetic activities in resident tumor cells at different stages of tumor progression. Mediated by molecular mechano-sensors or -transducers, biomechanical cues in tissue microenvironments are transmitted into the tumor cells and regulate biochemical responses and gene expression through mechanotransduction processes. However, the molecular interplay between the mechanotransduction processes and intracellular biochemical signaling pathways remains elusive. This paper reviews the recent advances in understanding the crosstalk between biomechanical cues and three critical biochemical effectors during tumor progression: calcium ions (Ca²⁺), yes-associated protein (YAP), and microRNAs (miRNAs). We address the molecular mechanisms underpinning the interplay between the mechanotransduction pathways and each of the three effectors. Furthermore, we discuss the functional interactions among the three effectors in the context of soft matter and mechanobiology. We conclude by proposing future directions on studying the tumor mechanobiology that can employ Ca²⁺, YAP, and miRNAs as novel strategies for cancer mechanotheraputics. This framework has the potential to bring insights into the development of novel next-generation cancer therapies to suppress and treat tumors.

Alterations of Ion Homeostasis in Cancer Metastasis: Implications for Treatment

We have previously reported that metastases from all malignancies are characterized by a core program of gene expression that suppresses extracellular matrix interactions, induces vascularization/tissue remodeling, activates the oxidative metabolism, and alters ion homeostasis. Among these features, the least elucidated component is ion homeostasis. Here we review the literature with the goal to infer a better mechanistic understanding of the progression-associated ionic alterations and identify the most promising drugs for treatment. Cancer metastasis is accompanied by skewing in calcium, zinc, copper, potassium, sodium and chloride homeostasis. Membrane potential changes and water uptake through Aquaporins may also play roles. Drug candidates to reverse these alterations are at various stages of testing, with some having entered clinical trials. Challenges to their utilization comprise differences among tumor types and the involvement of multiple ions in each case. Further, adverse effects may become a concern, as channel blockers, chelators, or supplemented ions will affect healthy and transformed cells alike.

Deep learning models for image and data processes of intracellular calcium ions

Intracellular calcium ion (Ca²⁺) in cytoplasm as an intracellular second messenger is involved in almost all important cellular activities of organisms. Generally its concentration ([Ca²⁺]_i) is tested by live imaging followed image and data processes, in which much tedious and subjective manual work is involved. Here we show a computational approach of Deep Calcium following the principles of deep learning to predict the cytoplasmic Ca²⁺ ranges and calcium peaks in calcium curve of objective cells. To validate Deep Calcium, chondrocytes, bone marrow stromal cells (BMSCs) and osteoblastic like cells (MC3T3-E1) from both the tissue and cell samples as well as from spontaneous and mechanical stimulated calcium response patterns are used. The good performance comparing with other relative machine learning models, as well as consistency biological results with human experts are demonstrated. Deep Calcium provides references for other image and data processes of intracellular range determination and curve peak identification.

TRPM7 Ion Channel: Oncogenic Roles and Therapeutic Potential in Breast Cancer

Simple Summary

Breast cancer is the most frequently diagnosed malignant tumor and the second leading cause of cancer death in women worldwide. The risk of developing breast cancer is 12.8%, i.e., 1 in 8 people, and a woman’s risk of dying is approximately 1 in 39. Calcium signals play an important role in various cancers and transport calcium ions may have altered expression in breast cancer, such as the TRPM7 calcium permeant ion channel, where overexpression may be associated with a poor prognosis. This review focuses on the TRPM7 channel, and the oncogenic roles studied so far in breast cancer. The TRPM7 ion channel is suggested as a potential and prospective target in the diagnosis and treatment of breast cancer.

Abstract

The transient receptor potential melastatin-subfamily member 7 (TRPM7) is a divalent cations permeant channel but also has intrinsic serine/threonine kinase activity. It is ubiquitously expressed in normal tissues and studies have indicated that it participates in important physiological and pharmacological processes through its channel-kinase activity, such as calcium/magnesium homeostasis, phosphorylation of proteins involved in embryogenesis or the cellular process. Accumulating evidence has shown that TRPM7 is overexpressed in human pathologies including breast cancer. Breast cancer is the second leading cause of cancer death in women with an incidence rate increase of around 0.5% per year since 2004. The overexpression of TRPM7 may be associated with a poor prognosis in breast cancer patients, so more efforts are needed to research a new therapeutic target. TRPM7 regulates the levels of Ca²⁺, which can alter the signaling pathways involved in survival, cell cycle progression, proliferation, growth, migration, invasion, epithelial-mesenchymal transition and thus determines cell behavior, promoting tumor development. This work provides a complete overview of the TRPM7 ion channel and its main involvements in breast cancer. Special consideration is given to the modulation of the channel as a potential target in breast cancer treatment by inhibition of proliferation, migration and invasion. Taken together, these data suggest the potential exploitation of TRPM7 channel-kinase as a therapeutic target and a diagnostic biomarker.

Prognostic Value of TRPM7 Expression and Factor XIIIa-Expressing Tumor-Associated Macrophages in Gastric Cancer

Purpose

TRPM7 is known to play a key role in tumor progression by regulating cellular proliferation, migration, and invasion in various cancer cell lines. However, there are no comprehensive clinical studies about the effect of TRPM7 expression on gastric cancer (GC) prognosis. In this study, it was aimed at investigating the effect of TRPM7 expression on prognosis in GC patients. Additionally, for the first time, it was investigated whether the density of Factor XIIIa-expressing tumor-associated macrophages (TAMs) in GC has an effect on the biological behaviour of the tumor.

Methods

TRPM7 expression and Factor XIIIa-expressing TAM density were immunohistochemically evaluated in paraffin-embedded tumor tissues of 204 GC patients undergoing surgery at a single institution.

Results

Tumor size was clearly higher in cases with high TRPM7 expression than those with low expression (p < 0.001, Mann-Whitney U). TRPM7 overexpression was closely related to high depth of tumor invasion (p < 0.001, ANOVA), increased lymph node metastasis (p < 0.001, ANOVA), and high distant metastasis rate (p < 0.001, Mann-Whitney U). These findings exposed that high TRPM7 expression is effective in the progression and aggressiveness of GC. In addition, while high CD8⁺ TIL density affects the prognosis positively, it was determined that high Factor XIIIa⁺ TAM density negatively affects the prognosis of patients with GC. Furthermore, multivariate analyses revealed TRPM7 overexpression was independently related with short overall (HR 9.64, 95% CI 5.74–16.19, p < 0.001) and disease-free survival (HR 5.67, 95% CI 3.61-8.92, p < 0.001) in GC patients.

Conclusions

Our data suggest that high TRPM7 expression is closely related to progressive tumor behaviour in GC and independently negatively affects survival in patients. In addition, it was determined that a high density of Factor XIIIa⁺ TAMs negatively affects the prognosis of patients with GC.

The role of calcium oscillations in the phenotype selection in endothelial cells

Angiogenesis is an important process in the formation and maintenance of tissues which is driven by a complex system of intracellular and intercellular signaling mechanisms. Endothelial cells taking part in early angiogenesis must select their phenotype as either a tip cells (leading, migratory) or a stalk cells (following). Recent experiments have demonstrated that rapid calcium oscillations within active cells characterize this phenotype selection process and that these oscillations play a necessary role in governing phenotype selection and eventual vessel architecture. In this work, we develop a mathematical model capable of describing these oscillations and their role in phenotype selection then use it to improve our understanding of the biological mechanisms at play. We developed a model based on two previously published and experimentally validated mathematical models of calcium and angiogenesis then use our resulting model to simulate various multi-cell scenarios. We are able to capture essential calcium oscillation dynamics and intercellular communication between neighboring cells. The results of our model show that although the late DLL4 (a transmembrane protein that activates Notch pathway) levels of a cell are connected with its initial IP3 (Inositol 1,4,5-trisphosphate) level, cell-to-cell communication determines its eventual phenotype.

Anti-inflammatory and anti-fibrotic effects of modafinil in nonalcoholic liver disease

Small- and intermediate-conductance Ca²⁺-activated K⁺ channels, K_Ca2.3 and K_Ca3.1, are involved in cellular signaling processes associated with inflammation and fibrosis. K_Ca2.3 and K_Ca3.1 are upregulated by proinflammatory cytokines and profibrotic growth factors. Cyclic AMP, which downregulates K_Ca2.3 and K_Ca3.1, is elevated by modafinil in cells; accordingly, we investigated whether modafinil exerts anti-inflammatory and anti-fibrotic responses via K_Ca2.3- and K_Ca3.1-mediated pathways in high-fat diet (HFD)- or thioacetamide-induced liver disease models in mice. Modafinil was administered orally in the form of a racemate, (R)-isomer, or (S)-isomer. We also determined whether the treatment targeted the profibrotic activity of hepatic stellate cells using immortalized human hepatic stellate cells (LX-2 cells). Modafinil improved HFD- or thioacetamide-induced changes compared to the control, leading to a reduced inflammatory response, collagen deposition, and α-smooth muscle actin expression both in vivo and in vitro. However, modafinil did not relieve HFD-induced steatosis. There were no significant differences in the effects of the (R)- and (S)-isomers of modafinil. K_Ca2.3 and K_Ca3.1 were upregulated and catalase was downregulated in liver tissues from thioacetamide- or HFD-induced liver disease models or in TGF-β-treated LX-2 cells. TGF-β-induced upregulation of K_Ca2.3, K_Ca3.1, collagen, and α-smooth muscle actin and downregulation of catalase were reversed by modafinil, polyethylene glycol catalase, N-acetylcysteine, siRNA against K_Ca2.3 or K_Ca3.1, and Epac inhibitors. Our investigation revealed that modafinil attenuated inflammatory and fibrotic progression via K_Ca2.3- and K_Ca3.1-mediated pathways in nonalcoholic hepatitis, suggesting that inhibiting K_Ca2.3- and K_Ca3.1-mediated signaling may serve as a novel therapeutic approach for inflammatory and fibrotic liver diseases.

Characterization of IL-2 Stimulation and TRPM7 Pharmacomodulation in NK Cell Cytotoxicity and Channel Co-Localization with PIP2 in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome Patients

Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a complex multisystemic disorder responsible for significant disability. Although a unifying etiology for ME/CFS is uncertain, impaired natural killer (NK) cell cytotoxicity represents a consistent and measurable feature of this disorder. Research utilizing patient-derived NK cells has implicated dysregulated calcium (Ca²⁺) signaling, dysfunction of the phosphatidylinositol-4,5-bisphosphate (PIP₂)-dependent cation channel, transient receptor potential melastatin (TRPM) 3, as well as altered surface expression patterns of TRPM3 and TRPM2 in the pathophysiology of ME/CFS. TRPM7 is a related channel that is modulated by PIP₂ and participates in Ca²⁺ signaling. Though TRPM7 is expressed on NK cells, the role of TRPM7 with IL-2 and intracellular signaling mechanisms in the NK cells of ME/CFS patients is unknown. This study examined the effect of IL-2 stimulation and TRPM7 pharmacomodulation on NK cell cytotoxicity using flow cytometric assays as well as co-localization of TRPM7 with PIP₂ and cortical actin using confocal microscopy in 17 ME/CFS patients and 17 age- and sex-matched healthy controls. The outcomes of this investigation are preliminary and indicate that crosstalk between IL-2 and TRMP7 exists. A larger sample size to confirm these findings and characterization of TRPM7 in ME/CFS using other experimental modalities are warranted.

Expression and associated epigenetic mechanisms of the Ca2+-signaling genes in breast cancer subtypes and epithelial-to-mesenchymal transition

Breast cancer-associated deaths are related mainly to specific molecular subtypes and the presence of metastasis. The Epithelial-to-Mesenchymal Transition (EMT) and Ca²⁺ signaling pathways are involved in breast cancer metastasis, and they are regulated in part by epigenetic mechanisms. Moreover, activation of EMT modulates Ca²⁺ concentration and in turn, Ca²⁺ signaling regulates the expression of EMT markers. Also, activation of Ca²⁺ signaling genes with epigenetic inhibitors reverts the EMT. Thus, Ca²⁺ signaling might have an important role in breast cancer metastasis and EMT, particularly through the epigenetic regulation of genes involved in its signaling. However, little is known due to that an estimate of 1670 genes participate in the Ca²⁺ signaling and only a few genes have been studied. Here, we aimed to explore the expression of all genes involved in Ca²⁺ signaling in all breast cancer subtypes and EMT, and whether modulation of epigenetic mechanisms is related to their expression. Several genes of the Ca²⁺ signaling are altered in all breast cancer subtypes, being the cadherins and voltage channels the most frequent altered genes. Also, DNA methylation and histone posttranslational modifications showed a good correlation with their altered expression. The expression of the cadherins and voltage channels is also modulated during breast EMT, and ATAC-seq results suggest that chromatin rearrangement at their promoter is involved. In conclusion, the expression of the genes involved in Ca²⁺ signaling is altered in all breast cancer subtypes and during EMT, and epigenetic mechanisms are an attractive target to regulate their expression.