LACTB Regulates PIK3R3 to Promote Autophagy and Inhibit EMT and Proliferation Through the PI3K/AKT/mTOR Signaling Pathway in Colorectal Cancer

Epigenetic silencing of KCTD8 promotes hepatocellular carcinoma growth by activating PI3K/AKT signaling

Aim: The aim of current study is to explore the epigenetic changes and function of KCTD8 in human hepatocellular carcinoma (HCC). Materials & methods: HCC cell lines and tissue samples were employed. Methylation specific PCR, flow cytometry, immunoprecipitation and xenograft mouse models were used. Results: KCTD8 was methylated in 44.83% (104/232) of HCC and its methylation may act as an independent poor prognostic marker. KCTD8 expression was regulated by DNA methylation. KCTD8 suppressed HCC cell growth both in vitro and in vivo via inhibiting PI3K/AKT pathway. Conclusion: Methylation of KCTD8 is an independent poor prognostic marker, and epigenetic silencing of KCTD8 increases the malignant tendency in HCC.

Mitochondrial proteases modulate mitochondrial stress signalling and cellular homeostasis in health and disease

Maintenance of mitochondrial homeostasis requires a plethora of coordinated quality control and adaptations' mechanisms in which mitochondrial proteases play a key role. Their activation or loss of function reverberate beyond local mitochondrial biochemical and metabolic remodelling into coordinated cellular pathways and stress responses that feedback onto the mitochondrial functionality and adaptability. Mitochondrial proteolysis modulates molecular and organellar quality control, metabolic adaptations, lipid homeostasis and regulates transcriptional stress responses. Defective mitochondrial proteolysis results in disease conditions most notably, mitochondrial diseases, neurodegeneration and cancer. Here, it will be discussed how mitochondrial proteases and mitochondria stress signalling impact cellular homeostasis and determine the cellular decision to survive or die, how these processes may impact disease etiopathology, and how modulation of proteolysis may offer novel therapeutic strategies.

Exploring the Key Signaling Pathways and ncRNAs in Colorectal Cancer

Colorectal cancer (CRC) is the third most prevalent cancer to be diagnosed, and it has a substantial mortality rate. Despite numerous studies being conducted on CRC, it remains a significant health concern. The disease-free survival rates notably decrease as CRC progresses, emphasizing the urgency for effective diagnostic and therapeutic approaches. CRC development is caused by environmental factors, which mostly lead to the disruption of signaling pathways. Among these pathways, the Wingless/Integrated (Wnt) signaling pathway, Phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) signaling pathway, Mitogen-Activated Protein Kinase (MAPK) signaling pathway, Transforming Growth Factor-β (TGF-β) signaling pathway, and p53 signaling pathway are considered to be important. These signaling pathways are also regulated by non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs). They have emerged as crucial regulators of gene expression in CRC by changing their expression levels. The altered expression patterns of these ncRNAs have been implicated in CRC progression and development, suggesting their potential as diagnostic and therapeutic targets. This review provides an overview of the five key signaling pathways and regulation of ncRNAs involved in CRC pathogenesis that are studied to identify promising avenues for diagnosis and treatment strategies.

Inhibition of PI3K/AKT signaling using BKM120 reduced the proliferation and migration potentials of colorectal cancer cells and enhanced cisplatin-induced cytotoxicity

BACKGROUND

Although extensive efforts have been made to improve the treatment of colorectal cancer (CRC) patients, the prognosis for these patients remains poor. A wide range of anti-cancer agents has been applied to ameliorate the clinical management of CRC patients; however, drug resistance develops in nearly all patients. Based on the prominent role of PI3K/AKT signaling in the development of CRC and current interest in the application of PI3K inhibitors, we aimed to disclose the exact mechanism underlying the efficacy of BKM120, a well-known pan-class I PI3K inhibitor, in CRC-derived SW480 cells.

MATERIALS AND METHODS

The effects of BKM120 on SW480 cells were studied using MTT assay, cell cycle assay, Annexin V/PI apoptosis tests, and scratch assay. In the next step, qRT-PCR was used to investigate the underlying molecular mechanisms by which the PI3K inhibitor could suppress the survival of SW480 cells.

RESULT

The results of the MTT assay showed that BKM120 could decrease the metabolic activity of SW480 cells in a concentration and time-dependent manner. Investigating the exact mechanism of BKM120 showed that this PI3K inhibitor induces its anti-survival effects through a G2/M cell cycle arrest and apoptosis-mediated cell death. Moreover, the scratch assay demonstrated that PI3K inhibition led to the inhibition of cancer invasion and inhibition of PI3K/AKT signaling remarkably sensitized SW480 cells to Cisplatin.

CONCLUSION

Based on our results, inhibition of PI3K/AKT signaling can be a promising approach, either as a single modality or in combination with Cisplatin. However, further clinical studies should be performed to improve our understanding.

A potential therapeutic approach for gastric cancer: inhibition of LACTB transcript 1

BACKGROUND

This study sought to investigate the role of LACTB transcript 1 in regulating adaptive immune resistance and stemness in gastric cancer and its potential as a therapeutic target for precision medicine.

METHODS

Bioinformatics analysis and RT-qPCR were used to analyze the expression level of LACTB and its transcripts in gastric cancer cells. The effects of LACTB transcript 1 on adaptive immune resistance and stemness were evaluated using in vitro cell experiments and western blotting experiments.

RESULTS

Our study findings revealed that LACTB transcript 1 modulated adaptive immune resistance and inhibited the stemness of gastric cancer cells. Knocking down the expression level of LACTB transcript 1 activated autophagy and inhibited EMT. As expected, overexpression of LACTB transcript 1 yielded the opposite findings. The expression level of LACTB transcript 1 in the peripheral blood of gastric cancer patients was consistent with the bioinformatics analysis, suggesting its potential as a biomarker of gastric cancer.

CONCLUSIONS

LACTB transcript 1 is a promising therapeutic target for precision medicine in gastric cancer by modulating immune evasion mechanisms and stemness. These findings provide insights into leveraging long non-coding RNAs (lncRNAs) in immunotherapy, radiotherapy, and chemotherapy to enhance cancer therapy efficacy, particularly in the context of targeting tumor heterogeneity and stemness.

The Prognosis of Cancer Depends on the Interplay of Autophagy, Apoptosis, and Anoikis within the Tumor Microenvironment

Within the tumor microenvironment, the fight between the immune system and cancer influences tumor transformation. Metastasis formation is an important stage in the progression of cancer. This process is aided by cellular detachment and resistance to anoikis, which are achieved by altering intercellular signaling. Autophagy, specifically pro-survival autophagy, aids cancer cells in developing treatment resistance. Numerous studies have shown that autophagy promotes tumor growth and resistance to anoikis. To regulate protective autophagy, cancer-related genes phosphorylate both pro- and anti-apoptotic proteins. Apoptosis, a type of controlled cell death, eliminates damaged or unwanted cells. Anoikis is a type of programmed cell death in which cells lose contact with the extracellular matrix. The dysregulation of these cellular pathways promotes tumor growth and spread. Apoptosis, anoikis, and autophagy interact meticulously and differently depending on the cellular circumstances. For instance, autophagy can protect cancer cells from apoptosis by removing cellular components that are damaged and might otherwise trigger apoptotic pathways. Similarly, anoikis dysregulation can trigger autophagy by causing cellular harm and metabolic stress. In order to prevent or treat metastatic disease, specifically, targeting these cellular mechanisms may present a promising prospect for cancer therapy. This review discourses the state of our understanding of the molecular and cellular mechanisms underlying tumor transformation and the establishment of metastatic tumors. To enhance the prognosis for cancer, we highlight and discuss potential therapeutic approaches that target these processes and genes involved in them.

Active compounds of Caodoukou () inhibit the migration, invasion and metastasis of human pancreatic cancer cells by targeting phosphoinosmde-3-kinase/ protein kinase B/mammalian target of rapamycin pathway

OBJECTIVE

To detect the effects of active compounds of Caodoukou () (ACAK) on the proliferation, migration and invasion of pancreatic cancer, and explain the possible molecular mechanism of ACAK interacting with these processes.

METHODS

Cell counting kit-8 method, cell scratch repair experiment, Transwell migration and invasion experiment, immunohistochemistry, western blot assay and real-time polymerase chain reaction experiment were used to evaluate the effect of ACAK on the proliferation, migration and invasion of pancreatic cancer cells. The levels of active molecules involved in the phosphoinosmde-3-kinase (PI3K)/Akt/the mammalian target of rapamycin (mTOR) signal transduction were detected by Western blot assay. In addition, the function of ACAK was evaluated by xenotransplantation tumor model in nude mice.

RESULTS

The inhibitory effect of ACAK on the proliferation of pancreatic cancer cells showed certain time-dose dependence. The results of scratch repair test, Transwell test, Western blotting and real time polymerase chain reaction assay showed that ACAK could inhibit the migration and invasion of pancreatic cancer cells . In addition, the regulatory effect of ACAK on epithelial-mesenchymal transition (EMT) is partly attributed to PI3K/Akt/mTOR signaling pathway. The experimental results showed that ACAK regulated the development of pancreatic cancer.

CONCLUSIONS

ACAK can partly inhibit the activity of EMT and matrix metallopeptidases by down-regulating the downstream proteins of PI3K/Akt/mTOR signal pathway, thus inhibiting the ability of migration and invasion of pancreatic cancer.

PI3K/AKT signaling pathway as a critical regulator of epithelial-mesenchymal transition in colorectal tumor cells

Colorectal cancer (CRC) is one of the most frequent gastrointestinal malignancies that are considered as a global health challenge. Despite many progresses in therapeutic methods, there is still a high rate of mortality rate among CRC patients that is associated with poor prognosis and distant metastasis. Therefore, investigating the molecular mechanisms involved in CRC metastasis can improve the prognosis. Epithelial-mesenchymal transition (EMT) process is considered as one of the main molecular mechanisms involved in CRC metastasis, which can be regulated by various signaling pathways. PI3K/AKT signaling pathway has a key role in CRC cell proliferation and migration. In the present review, we discussed the role of PI3K/AKT pathway CRC metastasis through the regulation of the EMT process. It has been shown that PI3K/AKT pathway can induce the EMT process by down regulation of epithelial markers, while up regulation of mesenchymal markers and EMT-specific transcription factors that promote CRC metastasis. This review can be an effective step toward introducing the PI3K/AKT/EMT axis to predict prognosis as well as a therapeutic target among CRC patients. Video Abstract.

Nanotechnology-empowered lung cancer therapy: From EMT role in cancer metastasis to application of nanoengineered structures for modulating growth and metastasis

Lung cancer is one of the leading causes of death in both males and females, and it is the first causes of cancer-related deaths. Chemotherapy, surgery and radiotherapy are conventional treatment of lung cancer and recently, immunotherapy has been also appeared as another therapeutic strategy for lung tumor. However, since previous treatments have not been successful in cancer therapy and improving prognosis and survival rate of lung tumor patients, new studies have focused on gene therapy and targeting underlying molecular pathways involved in lung cancer progression. Nanoparticles have been emerged in treatment of lung cancer that can mediate targeted delivery of drugs and genes. Nanoparticles protect drugs and genes against unexpected interactions in blood circulation and improve their circulation time. Nanoparticles can induce phototherapy in lung cancer ablation and mediating cell death. Nanoparticles can induce photothermal and photodynamic therapy in lung cancer. The nanostructures can impair metastasis of lung cancer and suppress EMT in improving drug sensitivity. Metastasis is one of the drawbacks observed in lung cancer that promotes migration of tumor cells and allows them to establish new colony in secondary site. EMT can occur in lung cancer and promotes tumor invasion. EMT is not certain to lung cancer and it can be observed in other human cancers, but since lung cancer has highest incidence rate, understanding EMT function in lung cancer is beneficial in improving prognosis of patients. EMT induction in lung cancer promotes tumor invasion and it can also lead to drug resistance and radio-resistance. Moreover, non-coding RNAs and pharmacological compounds can regulate EMT in lung cancer and EMT-TFs such as Twist and Slug are important modulators of lung cancer invasion that are discussed in current review.

Towards dual function of autophagy in breast cancer: A potent regulator of tumor progression and therapy response

As a devastating disease, breast cancer has been responsible for decrease in life expectancy of females and its morbidity and mortality are high. Breast cancer is the most common tumor in females and its treatment has been based on employment of surgical resection, chemotherapy and radiotherapy. The changes in biological behavior of breast tumor relies on genomic and epigenetic mutations and depletions as well as dysregulation of molecular mechanisms that autophagy is among them. Autophagy function can be oncogenic in increasing tumorigenesis, and when it has pro-death function, it causes reduction in viability of tumor cells. The carcinogenic function of autophagy in breast tumor is an impediment towards effective therapy of patients, as it can cause drug resistance and radio-resistance. The important hallmarks of breast tumor such as glucose metabolism, proliferation, apoptosis and metastasis can be regulated by autophagy. Oncogenic autophagy can inhibit apoptosis, while it promotes stemness of breast tumor. Moreover, autophagy demonstrates interaction with tumor microenvironment components such as macrophages and its level can be regulated by anti-tumor compounds in breast tumor therapy. The reasons of considering autophagy in breast cancer therapy is its pleiotropic function, dual role (pro-survival and pro-death) and crosstalk with important molecular mechanisms such as apoptosis. Moreover, current review provides a pre-clinical and clinical evaluation of autophagy in breast tumor.

LACTB induces cancer cell death through the activation of the intrinsic caspase-independent pathway in breast cancer

BACKGROUND

LACTB was recently identified as a mitochondrial tumour suppressor that negatively affects cancer cell proliferation by inducing cell death and/or differentiation, depending on the cell type and tissue. However, the detailed mechanism underlying the LACTB-induced cancer cell death is largely unknown.

METHODS

We used cell-based, either in 2D or 3D conditions, and in vivo experiments to understand the LACTB mechanisms. In this regard, protein array followed by an enrichment analysis, cell proliferation assays using different compounds, western blot analysis, flow cytometry and immunofluorescence were performed. Differences between quantitative variables following normal distribution were valuated using Student t test for paired or no-paired samples according to the experiment. For in vivo experiments differences in tumour growth were analyzed by 2-way ANOVA.

RESULTS

We show, that LACTB expression leads to cell cycle arrest in G1 phase and increase of DNA oxidation that leads to activation of intrinsic caspase-independent cell death pathway. This is achieved by an increase of mitochondrial reactive oxygen species since early time points of LACTB induction.

CONCLUSION

Our work provides a deeper mechanistic insight into LACTB-mediated cancer-cell death and shows the dynamics of the cellular responses a particular tumor suppressive stimulus might evoke under different genetic landscapes.

LACTB exerts tumor suppressor properties in epithelial ovarian cancer through regulation of Slug

Epithelial-mesenchymal transition (EMT) is a cellular mechanism used by cancer cells to acquire migratory and stemness properties. In this study, we show, through in vitro, in vivo, and 3D culture experiments, that the mitochondrial protein LACTB manifests tumor suppressor properties in ovarian cancer. We show that LACTB is significantly down-regulated in epithelial ovarian cancer cells and clinical tissues. Re-expression of LACTB negatively effects the growth of cancer cells but not of non-tumorigenic cells. Mechanistically, we show that LACTB leads to differentiation of ovarian cancer cells and loss of their stemness properties, which is achieved through the inhibition of the EMT program and the LACTB-dependent down-regulation of Snail2/Slug transcription factor. This study uncovers a novel role of LACTB in ovarian cancer and proposes new ways of counteracting the oncogenic EMT program in this model system.

The structure of the human LACTB filament reveals the mechanisms of assembly and membrane binding

Mitochondria are complex organelles that play a central role in metabolism. Dynamic membrane-associated processes regulate mitochondrial morphology and bioenergetics in response to cellular demand. In tumor cells, metabolic reprogramming requires active mitochondrial metabolism for providing key metabolites and building blocks for tumor growth and rapid proliferation. To counter this, the mitochondrial serine beta-lactamase-like protein (LACTB) alters mitochondrial lipid metabolism and potently inhibits the proliferation of a variety of tumor cells. Mammalian LACTB is localized in the mitochondrial intermembrane space (IMS), where it assembles into filaments to regulate the efficiency of essential metabolic processes. However, the structural basis of LACTB polymerization and regulation remains incompletely understood. Here, we describe how human LACTB self-assembles into micron-scale filaments that increase their catalytic activity. The electron cryo-microscopy (cryoEM) structure defines the mechanism of assembly and reveals how highly ordered filament bundles stabilize the active state of the enzyme. We identify and characterize residues that are located at the filament-forming interface and further show that mutations that disrupt filamentation reduce enzyme activity. Furthermore, our results provide evidence that LACTB filaments can bind lipid membranes. These data reveal the detailed molecular organization and polymerization-based regulation of human LACTB and provide new insights into the mechanism of mitochondrial membrane organization that modulates lipid metabolism.

Chemoprevention of 4NQO-Induced Mouse Tongue Carcinogenesis by AKT Inhibitor through the MMP-9/RhoC Signaling Pathway and Autophagy

Oral cancer (OC), the most common cancer in the head and neck, which has a poor prognosis, histopathologically follows a stepwise pattern of hyperplasia, dysplasia, and cancer. Blocking the progression of OC in the precancer stage could greatly improve the survival and cure rates. AKT protein plays a critical role in the signal transduction of cancer cells, and we found that AKT was overexpressed in human OC samples through analysis of TCGA database. Therefore, this study is aimed at investigating the chemopreventive effect of an AKT inhibitor (MK2206 2HCl) on OC. In vivo, we established a 4-nitroquinoline-1-oxide- (4NQO-) induced mouse tongue carcinogenesis model to investigate the potential chemopreventive effect of MK2206 2HCl on mouse OC resulting from 4NQO. The results showed that MK2206 2HCl could significantly reduce the incidence rate and growth of OC, inhibit the transformation of dysplasia to cancer in the 4NQO-induced mouse tongue carcinogenesis model, and simultaneously markedly suppress cell proliferation, angiogenesis, and mast cell (MC) infiltration in 4NQO-induced mouse tongue cancers. In vitro, our results revealed that MK2206 2HCl could also inhibit oral squamous cell carcinoma (OSCC) cell malignant biological behaviors, including cell proliferation, colony formation, cell invasion, and migration, while promoting apoptosis. Mechanistic studies revealed that MK2206 2HCl suppressed matrix metalloproteinase 9 (MMP-9) and RhoC expression and promoted autophagy gene LC3 II expression. In summary, our findings demonstrated the chemopreventive effect of MK2206 2HCl on the 4NQO-induced mouse tongue carcinogenesis model, which likely has an underlying mechanism mediated by the MMP-9/RhoC signaling pathway and autophagy.

LACTB, a Metabolic Therapeutic Target in Clinical Cancer Application

Serine beta-lactamase-like protein (LACTB) is the only mammalian mitochondrial homolog evolved from penicillin-binding proteins and β-lactamases (PBP-βLs) in bacteria. LACTB, an active-site serine protease, polymerizes into stable filaments, which are localized to the intermembrane space (IMS) of mitochondrion and involved in the submitochondrial organization, modulating mitochondrial lipid metabolism. Cancer pathogenesis and progression are relevant to the alterations in mitochondrial metabolism. Metabolic reprogramming contributes to cancer cell behavior. This article (1) evidences the clinical implications of LACTB on neoplastic cell proliferation and migration and tumor growth and metastasis as well as LACTB’s involvement in chemotherapeutic and immunotherapeutic responses; (2) sketches the structural basis for LACTB activity and function; and (3) highlights the relevant regulatory mechanisms to LACTB. The abnormal expression of LACTB has been associated with clinicopathological features of cancer tissues and outcomes of anticancer therapies. With the current pioneer researches on the tumor-suppressed function, structural basis, and regulatory mechanism of LACTB, the perspective hints at a great appeal of enzymic property, polymerization, mutation, and epigenetic and post-translational modifications in investigating LACTB’s role in cancer pathogenesis. This perspective provides novel insights for LACTB as a metabolic regulator with potential to develop targeted cancer therapies or neoadjuvant therapeutic interventions.

HDAC8 Promotes Liver Metastasis of Colorectal Cancer via Inhibition of IRF1 and Upregulation of SUCNR1

Histone deacetylases (HDACs) are well-characterized for their involvement in tumor progression. Herein, the current study set out to unravel the association of HDAC8 with colorectal cancer (CRC). Bioinformatics analyses were carried out to retrieve the expression patterns of HDAC8 in CRC and the underlying mechanism. Following expression determination, the specific roles of HDAC8, IRF1, and SUCNR1 in CRC cell functions were analyzed following different interventions. Additionally, tumor formation and liver metastasis in nude mice were operated to verify the fore experiment. Bioinformatics analyses predicted the involvement of the HDAC8/IRF1/SUCNR1 axis in CRC. In vitro cell experiments showed that HDAC8 induced the CRC cell growth by reducing IRF1 expression. Meanwhile, IRF1 limited SUCNR1 expression by binding to its promoter. SUCNR1 triggered the growth and metastasis of CRC by inhibiting cell autophagy. HDAC8 blocked IRF1-mediated SUCNR1 inhibition and thereby inhibited autophagy, accelerating CRC cell growth. Lastly, HDAC8 facilitated the development of CRC and liver metastasis by regulating the IRF1/SUCNR1 axis in vivo. Taken together, our findings highlighted the critical role for the HDAC8/IRF1/SUCNR1 axis in the regulation of autophagy and the resultant liver metastasis in CRC.

Autophagy: A Versatile Player in the Progression of Colorectal Cancer and Drug Resistance

Colorectal cancer (CRC) is among the topmost malignancies for both genders. Despite the high incidence rate and advances in diagnostic tools, treatment in many cases is still ineffective. Most cancerous lesions in CRC begin as benign, followed by the development of invasive forms and metastases. The development of CRC has been linked to defects in autophagy, which plays both a pro-and anti-tumor role and is mainly context-dependent. Autophagy suppression could enhance apoptosis via p53 activation, or autophagy also promotes tumor progression by maintaining tumor growth and increasing resistance to chemotherapy. Autophagy promotes the invasion and metastasis of CRC cells via increased epithelial-mesenchymal transition (EMT). Moreover, dysbiosis of gut microbiota upregulated autophagy and metastasis markers. Autophagy responses may also modulate the tumor microenvironment (TME) via regulating the differentiation process of several innate immune cells. Treatments that promote tumor cell death by stimulating or inhibiting autophagy could be beneficial if used as an adjunct treatment, but the precise role of various autophagy-modulating drugs in CRC patients is needed to be explored. In this article, we present an overview of the autophagy process and its role in the pathogenesis and therapeutic resistance of CRC. Also, we focused on the current understanding of the role of the EMT and TME, including its relation to gut microbiota and immune cells, in autophagic manipulation of CRC. We believe that there is a potential link between autophagy, TME, EMT, and drug resistance, suggesting that further studies are needed to explore this aspect.

Emodin inhibits invasion and migration of hepatocellular carcinoma cells via regulating autophagy-mediated degradation of snail and β-catenin

Background

Previous studies reported that emodin extracted from Rheum palmatum L. exerts antiproliferation and antimetastatic effects in a variety of human cancer types. However, the role of emodin in hepatocellular carcinoma (HCC) remain unknown.

Methods

EdU and colony formation assays were performed to evaluate the effects of emodin on proliferation. The mobility capacities of HCC treated with emodin were evaluated using wound healing assay. Transwell invasion and migration assays were performed to evaluate anti-migratory and anti-invasive effects of emodin on HCC. Annexin V-FITC/PI was performed to analyze the apoptosis. PI stain was performed to analyze cell cycle. RNA sequencing technology was used to identify the differentially expressed genes (DEGs) induced by emodin in HCC. The impact of emodin on autophagic flux in HepG2 cells was examined by mCherry-GFP-LC3 analysis. Western blot was used to assess the protein expressions of epithelial-mesenchymal transition (EMT), autophagy, PI3K/AKT/mTOR and Wnt/β-catenin signaling pathway.

Results

We found that emodin inhibited the growth of HepG2 cells in a dose- and time-dependent manner. In addition, emodin inhibited cell proliferation, induced S and G2/M phases arrest, and promoted apoptosis in HepG2 cells. The migration and invasion of HepG2 cells were also suppressed by emodin. Enrichment analysis revealed that DEGs involved in cell adhesion, cancer metastasis and cell cycle arrest. Moreover, western bolt results show that emodin-induced autophagy promotes Snail and β-catenin degradation. We also found that blocking autophagic flux after emodin treatment caused EMT reversal. Furthermore, the PI3K agonist Y-P 740 significantly reversed the phosphorylation levels of GSK3β and mTOR. These results indicated that emodin induced autophagy and inhibited the EMT in part through suppression of the PI3K/AKT/mTOR and Wnt/β-catenin pathways.

Conclusion

Our study indicated that emodin inhibited cell metastasis in HCC via the crosstalk between autophagy and EMT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09684-0.

Unveiling the Function of the Mitochondrial Filament-Forming Protein LACTB in Lipid Metabolism and Cancer

LACTB is a relatively unknown mitochondrial protein structurally related to the bacterial penicillin-binding and beta-lactamase superfamily of serine proteases. LACTB has recently gained an increased interest due to its potential role in lipid metabolism and tumorigenesis. To date, around ninety studies pertaining to LACTB have been published, but the exact biochemical and cell biological function of LACTB still remain elusive. In this review, we summarise the current knowledge about LACTB with particular attention to the implications of the recently published study on the cryo-electron microscopy structure of the filamentous form of LACTB. From this and other studies, several specific properties of LACTB emerge, suggesting that the protein has distinct functions in different physiological settings. Resolving these issues by further research may ultimately lead to a unified model of LACTB’s function in cell and organismal physiology. LACTB is the only member of its protein family in higher animals and LACTB may, therefore, be of particular interest for future drug targeting initiatives.

Structural basis for the catalytic activity of filamentous human serine beta-lactamase-like protein LACTB

Serine beta-lactamase-like protein (LACTB) is a mammalian mitochondrial serine protease that can specifically hydrolyze peptide bonds adjacent to aspartic acid residues and is structurally related to prokaryotic penicillin-binding proteins. Here, we determined the cryoelectron microscopy structures of human LACTB (hLACTB) filaments from wild-type protein, a middle region deletion mutant, and in complex with the inhibitor Z-AAD-CMK at 3.0-, 3.1-, and 2.8-Å resolution, respectively. Structural analysis and activity assays revealed that three interfaces are required for the assembly of hLACTB filaments and that the formation of higher order helical structures facilitates its cleavage activity. Further structural and enzymatic analyses of middle region deletion constructs indicated that, while this region is necessary for substrate hydrolysis, it is not required for filament formation. Moreover, the inhibitor-bound structure showed that hLACTB may cleave peptide bonds adjacent to aspartic acid residues. These findings provide the structural basis underlying hLACTB catalytic activity.

LACTB suppresses carcinogenesis in lung cancer and regulates the EMT pathway

Lung cancer causes thousands of deaths worldwide every year, and present therapeutics show little benefit for advanced-stage patients. Researchers do not know why and how lung cancer begins. Lactamase β (LACTB) is a tumor-suppressor in some cancers. However, its role in lung cancer is unknown. By analyzing the TCGA database and Kaplan-Meier Plotter database, LACTB was found to be downregulated in lung cancer tissues but the methylation level was increased. Patients with high LACTB expression exhibited improved survival. Then, in vitro assays demonstrated that LACTB overexpression inhibited cell migration and invasion, and induced apoptosis in H1299 and H1975 cells. Knockdown of LACTB caused the reverse effects. Moreover, a much higher apoptotic rate and more potent inhibitory effects on H1299 and H1975 cells were obtained when LACTB was combined with docetaxel. In addition, members of the epithelial-mesenchymal transition (EMT) signaling pathway were assessed using western blot analysis. The expression of E-cadherin was decreased while levels of N-cadherin and vimentin were increased after knockdown of LACTB in lung cancer cells. By contrast, overexpression of LACTB increased the level of E-cadherin but decreased N-cadherin and vimentin. Therefore, LACTB is a tumor suppressor in lung cancer that inhibits cell migration and invasion and induces cell apoptosis. Meanwhile, LACTB was found to strengthen the anticancer role of docetaxel and to suppress the EMT pathway in lung cancer.

Regulatory effects of lncRNAs and miRNAs on the crosstalk between autophagy and EMT in cancer: a new era for cancer treatment

PURPOSE

Autophagy and EMT (epithelial-mesenchymal transition) are the two principal biological processes and ideal therapeutic targets during cancer development. Autophagy, a highly conserved process for degrading dysfunctional cellular components, plays a dual role in tumors depending on the tumor stage and tissue types. The EMT process is the transition differentiation from an epithelial cell to a mesenchymal-like cell and acquiring metastatic potential. There is evidence that the crosstalk between autophagy and EMT is complex in cancer. In recent years, more studies have shown that long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) are involved in autophagy, EMT, and their crosstalk. Therefore, accurate understanding of the regulatory mechanisms of lncRNAs and miRNAs in autophagy, EMT and their interactions is crucial for the clinical management of cancers.

METHODS

An extensive literature search was conducted on the Google Scholar and PubMed databases. The keywords used for the search included: autophagy, EMT, crosstalk, lncRNAs, miRNAs, cancers, diagnostic biomarkers, and therapeutic targets. This search provided relevant articles published in peer-reviewed journals until 2021. Data from these various studies were extracted and used in this review.

RESULTS

The results showed that lncRNAs/miRNAs as tumor inhibitors or tumor inducers could regulate autophagy, EMT, and their interaction by regulating several molecular signaling pathways. The lncRNAs/miRNAs involved in autophagy and EMT processes could have potential uses in cancer diagnosis, prognosis, and therapy.

CONCLUSION

Such information could help find and develop lncRNAs/miRNAs based new tools for diagnosing, prognosis, and creating anti-cancer therapies.

Epithelial-mesenchymal transition process during embryo implantation

The epithelial to mesenchymal transition (EMT) in endometrial epithelial and trophectoderm cells is essential for the progression of embryo implantation and its impairment could cause implantation failure. Therefore, EMT should be tightly regulated in both embryonic and endometrial cells during implantation. Studies reported the involvement of numerous factors in EMT regulation, including hormones, growth factors, transcription factors, microRNAs, aquaporins (AQPs), and ion channels. These factors act through different signaling pathways to affect the expression of epithelial and mesenchymal markers as well as the cellular cytoskeleton. Although the mechanisms involved in cancer cell EMT have been well studied, little is known about EMT during embryo implantation. Therefore, we comprehensively reviewed different factors that regulate the EMT, a key event required for the conceptus implantation to the endometrium.Summary sentence: Abnormal epithelial-mesenchymal transition (EMT) process within endometrial epithelial cells (EECs) or trophoblast cells can cause implantation failure. This process is regulated by various factors. Thus, the objective of this review was to summarize the effective factors on the EMT process during implantation.

Tetraspanin 1 (TSPAN1) promotes growth and transferation of breast cancer cells via mediating PI3K/Akt pathway

The incidence and mortality of breast cancer rank first among all types of female tumors. To improve patients’ prognosis with advanced breast cancer, new and more effective targets still need to be explored and identified. Tetraspanin 1 (TSPAN1) is highly expressed in several cancers and affects the progression of these tumors. However, there are few studies focused on its role in breast cancer. Previous study showed that TSPAN1 promoted epithelial-mesenchymal transition (EMT) and metastasis, and whether TSPAN1 could promote breast cancer via regulating EMT needs further study. In this study, we found high TSPAN1 expression in breast cancer tumor samples and cell lines which was confirmed by bioinformation analysis. The ablation of TSPAN1 suppressed the growth, and motility of breast cancer cells. We further found that TSPAN1 affected the EMT and mediated the PI3K/Akt pathway in breast cancer cells. In addition, TSPAN1 depletion suppressed tumor growth of breast cancer in mice. In summary, we thought TSPAN1 suppressed growth and motility of breast cancer via mediating EMT and PI3K/AKT pathway, and could serve as a potential target for treatment of breast cancer.

Circ_0045714/miR-331-3p interaction affects IL-1β-evoked human articular chondrocyte injury through regulating PIK3R3 in a ceRNA regulatory cascade

BACKGROUND

Osteoarthritis (OA) is characterized by joint pain and joint function limitation. Hsa_circ_0045714 (circ_0045714) is a novel OA-related circular RNA. However, its repertoire remains to be further clarified in joint chondrocytes.

METHODS

RNA and protein expression levels and inflammatory factor levels were detected by real-time quantitative polymerase chain reaction, western blotting and enzyme-linked immunosorbent assay. Cell proliferation and apoptosis were determined by colony formation assay, cell counting kit-8 assay and apoptosis assay. Direct interaction was predicted by bioinformatics method and confirmed by dual-luciferase reporter assay.

RESULTS

Expression of circ_0045714 and phosphoinositide-3-kinase (PI3K) regulatory subunit 3 (PIK3R3) was declined, and microRNA (miR)-331-3p was promoted in knee articular cartilages and cells from OA patients, as well as interleukin (IL)-1β-challenged human articular chondrocytes (HAC) cell line. In stimulation of IL-1β, HAC cells showed a loss of colony formation ability, cell viability and expression of Bcl-2 and Collagen II, allied with an increase in apoptosis rate and levels of IL-6, IL-8 and tumor necrosis factor-α, Bcl-2-associated X protein, cleaved caspase-3, and ADAM with thrombospondin motif-5. Noticeably, overexpressing circ_0045714 and inhibiting miR-331-3p could suppress IL-1β-evoked these effects, and both were through up-regulating PIK3R3, a key gene in PI3K/AKT signaling pathway. Mechanically, circ_0045714 functioned as competing endogenous RNA (ceRNA) for miR-331-3p and further regulated expression of the downstream target gene PIK3R3.

CONCLUSION

There was a novel circ_0045714/miR-331-3p/PIK3R3 ceRNA axis in HAC, and its inhibition might be one mechanism of HAC injury in OA.

Growth Factors, PI3K/AKT/mTOR and MAPK Signaling Pathways in Colorectal Cancer Pathogenesis: Where Are We Now?

Colorectal cancer (CRC) is a predominant malignancy worldwide, being the fourth most common cause of mortality and morbidity. The CRC incidence in adolescents, young adults, and adult populations is increasing every year. In the pathogenesis of CRC, various factors are involved including diet, sedentary life, smoking, excessive alcohol consumption, obesity, gut microbiota, diabetes, and genetic mutations. The CRC tumor microenvironment (TME) involves the complex cooperation between tumoral cells with stroma, immune, and endothelial cells. Cytokines and several growth factors (GFs) will sustain CRC cell proliferation, survival, motility, and invasion. Epidermal growth factor receptor (EGFR), Insulin-like growth factor -1 receptor (IGF-1R), and Vascular Endothelial Growth Factor -A (VEGF-A) are overexpressed in various human cancers including CRC. The phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) and all the three major subfamilies of the mitogen-activated protein kinase (MAPK) signaling pathways may be activated by GFs and will further play key roles in CRC development. The main aim of this review is to present the CRC incidence, risk factors, pathogenesis, and the impact of GFs during its development. Moreover, the article describes the relationship between EGF, IGF, VEGF, GFs inhibitors, PI3K/AKT/mTOR-MAPK signaling pathways, and CRC.

Mitochondrial Tumor Suppressors-The Energetic Enemies of Tumor Progression

Tumor suppressors represent a critical line of defense against tumorigenesis. Their mechanisms of action and the pathways they are involved in provide important insights into cancer progression, vulnerabilities, and treatment options. Although nuclear and cytosolic tumor suppressors have been extensively investigated, relatively little is known about tumor suppressors localized within the mitochondria. However, recent research has begun to uncover the roles of these important proteins in suppressing tumorigenesis. Here, we review this newly developing field and summarize available information on mitochondrial tumor suppressors.

A study on the potential role of autophagy-related protein 10 as a biomarker for ulcerative colitis

PURPOSE

Ulcerative colitis (UC) is a lifelong disease with unclear etiology and increasing prevalence worldwide. Autophagy has been reported to play roles in the pathogenesis and progression of UC. Here, we aimed to analyze the expression of autophagy related protein 10 (ATG10) and its regulator, micro-RNA (miR) 519a, in UC patients.

METHODS

The level of ATG10 in the serum, stool, and colon biopsies from 15 UC patients and 30 non-UC healthy individuals (HC) group was measured by ELISA. Also, the blood level of miR-519a was investigated by quantitative real-time PCR.

RESULTS

We found 13.63 ng/ml versus 0.99 ng/ml, 11.01 ng/ml versus 1.11 ng/ml and 6.41 ng/ml versus 3.21 ng/ml of ATG10 in the stool, colon tissue, and serum of UC and HC, respectively. There was no significant difference in the expression of miR-519a in the blood samples of UC and HC.

CONCLUSIONS

ATG10 might be a potential non-invasive diagnostic biomarker for UC.

MiR-93/HMGB3 regulatory axis exerts tumor suppressive effects in colorectal carcinoma cells

OBJECTIVE

MicroRNA (miR)-93 has been proven to mediate the initiation and progression of colorectal carcinoma (CRC); however, the mechanisms by which miR-93 mediates CRC development need deeper elucidation. The present study is designed to investigate the association between miR-93 and high mobility group box 3 (HMGB3), as well as the functions of miR-93, in CRC.

METHODS

miR-93 expression was quantified by RT-qPCR. CRC cells were transfected or cotransfected with miR-93 mimic, miR-93 inhibitor, pcDNA3.1-HMGB3 and sh-HMGB3, and then the proliferative, migratory and invasive capacities were detected in addition to the apoptotic rate. Western blotting assessed the expression levels of HMGB3, PI3K, p-PI3K, AKT and p-AKT. The interaction between miR-93 and HMGB3 was identified.

RESULTS

In CRC tissues, miR-93 was downregulated and HMGB3 was upregulated. LOVO and SW480 cells transfected with miR-93 mimic exhibited reduced proliferation, invasion and migration as well as increased apoptosis. The ratios of p-PI3K/PI3K and p-AKT/AKT were declined after miR-93 mimic was introduced into the CRC cell lines. miR-93 negatively downregulated HMGB3, and introduction of pcDNA3,1-HMGB3 could counteract, in part, the inhibitory effects of miR-93 on the malignant properties of CRC cells as well as the ratios of p-PI3K/PI3K and p-AKT/AKT.

CONCLUSION

miR-93 targeted HMGB3 to block the activation of the PI3K/AKT pathway and thus enhance CRC cell apoptosis.

The depletion of Circ-PRKDC enhances autophagy and apoptosis in T-cell acute lymphoblastic leukemia via microRNA-653-5p/Reelin mediation of the PI3K/AKT/mTOR signaling pathway

A range of circular (Circ) RNAs have been demonstrated to be of therapeutic significance for the treatment of acute lymphoblastic leukemia (ALL). Here, we investigated the mechanisms underlying the action of Circ-PRKDC and the microRNA-653-5p/Reelin (miR-653-5p/RELN) axis in T-cell ALL (T-ALL).Clinical specimens were obtained from patients with T-ALL (n = 39) and healthy controls (n = 30). In each specimen, we determined the expression levels of Circ-PRKDC, miR-653-5p, and RELN. Human T-ALL cells (Jurkat) were transfected with Circ-PRKDC- or miR-653-5p-related sequences to investigate cell proliferation, apoptosis, and autophagy. We also determined the levels of Circ-PRKDC, miR-653-5p, RELN, and signaling proteins related to phosphoinositide 3-kinase (PI3K), AKT, and mammalian target of rapamycin (mTOR). Finally, we decoded the interactions between Circ-PRKDC, miR-653-5p, and RELN. The expression levels of Circ-PRKDC and RELN were upregulated in T-ALL tissues and cells while the levels of miR-653-5p were downregulated. Thereafter, then silencing of Circ-PRKDC, or the enforced expression of miR-653-5p, repressed the expression of RELN and the activation of the PI3K/AKT/mTOR signaling pathway, thus enhancing cell autophagy and apoptosis, and disrupting cell proliferation. Circ-PRKDC acted a sponge for miR-653-5p while miR-653-5p targeted RELN. The knockdown of miR-653-5p abrogated the silencing of Circ-PRKDC-induced effects in T-ALL cells. The depletion of Circ-PRKDC elevated miR-653-5p to silence RELN-mediated PI3K/AKT/mTOR signaling activation, thereby enhancing autophagy and apoptosis in T-ALL cells.

LACTB induced apoptosis of oxaliplatin-resistant gastric cancer through regulating autophagy-mediated mitochondrial apoptosis pathway

Oxaliplatin (OXA), as a third-generation platinum anticancer drug, is a treatment drug for gastric cancer (GC). However, OXA resistance has become the main reason for OXA treatment failure. Serine beta-lactamase-like protein (LACTB), acts as a mitochondrial protein, can affect multiple cancer processes. Here, we aimed to investigate the function and mechanism of LACTB in OXA-resistant GC. After LACTB overexpression or autophagy activator (RAPA) treatment, cell proliferation, reactive oxygen species (ROS), apoptosis, mitochondrial dysfunction were evaluated through CCK-8 assay, Edu staining, flow cytometry and immunofluorescence assay. Moreover, DNA double-stranded damage and autophagy-related proteins were examined via western blot. We revealed that LACTB was downregulated in OXA-resistant MGC-803 cells, and overexpression of LACTB reduced the resistance of GC cells to OXA. Besides, our results uncovered that overexpression of LACTB induced apoptosis, reduced the mitochondrial membrane potential (MMP) and accelerated ROS accumulation in OXA-resistant MGC-803 (MGC-803/OXA) cells. Meanwhile, we verified that overexpression of LACTB decreased glucose uptake and ATP synthesis, induced mitochondria and DNA damages, and inhibited autophagy of MGC-803/OXA cells. Furthermore, our results certified that RAPA could weaken the function of LACTB on apoptosis and mitochondrial morphology and function in OXA-resistant MGC-803 cells with OXA treatment. Therefore, we demonstrated that LACTB could attenuate the resistance of MGC-803/OXA cells to OXA through autophagy-mediated mitochondrial morphological changes, mitochondrial dysfunction, and apoptosis, suggesting that LACTB, functions as a suppressor, is conducive to the therapy of OXA-resistant GC.

Pinocembrin Inhibits the Proliferation, Migration, Invasiveness, and Epithelial-Mesenchymal Transition of Colorectal Cancer Cells by Regulating LACTB

Background: Colorectal cancer (CRC) is a common malignancy of digestive tract. Pinocembrin (PINO) has been discovered to have proapoptotic effect on CRC. This study aimed to elucidate how other biological behaviors of CRC cells were affected under PINO treatment. Materials & Methods: The effect of PINO on HT29 and HCT116 cells were detected through treatment of different concentrations of PINO. The role of LACTB in PINO treatment was investigated by transfection of siRNA-LACTB. Cell counting kit-8 assay, wound healing assay, and Transwell assay were conducted to evaluate the proliferation, migration, and invasiveness of CRC cells, respectively. Western blot or quantitative reverse transcription-polymerase chain reaction was carried out to measure the expressions of LACTB, matrix metalloproteinase (MMP)-2, E-cadherin, and N-cadherin. Results: Gradient PINO inhibited the viability, migration, invasiveness, and expressions of MMP-2 and N-cadherin in CRC cells, while promoted E-cadherin and LACTB expressions. Silencing LACTB promoted the viability, migration, invasiveness, and expressions of MMP-2 and N-cadherin in CRC cells and inhibited E-cadherin expression. PINO counteracted the effect of silenced LACTB, and yet silencing LACTB partially abolished the effect of PINO on CRC cells. Conclusion: PINO inhibited the proliferation, migration, invasiveness, and epithelial-to-mesenchymal transition of CRC cells by regulating LACTB.

CircRNA_0000392 promotes colorectal cancer progression through the miR-193a-5p/PIK3R3/AKT axis

Background

Circular RNAs (circRNAs), important members of the noncoding RNA family, have been recently revealed to play a role in the pathogenic progression of diseases, particularly in the malignant progression of cancer. With the application of high-throughput sequencing technology, a large number of circRNAs have been identified in tumor tissues, and some circRNAs have been demonstrated to act as oncogenes. In this study, we analyzed the circRNA expression profile in colorectal cancer (CRC) tissues and normal adjacent tissues by high-throughput sequencing. We focused on circRNA_0000392, a circRNA with significantly increased expression in CRCtissues, and further investigated its function in the progression of colorectal cancer.

Methods

The expression profile of circRNAs in 6 pairs of CRC tissues and normal adjacent tissues was analyzed by RNA sequencing. We verified the identified differentially expressed circRNAs in additional samples by qRT-PCR and selected circRNA_0000392 to evaluate its associations with clinicopathological features. Then, we knocked down circRNA_0000392 in CRC cells and investigated the in vitro and in vivo effects using functional experiments. Dual luciferase and RNA pull-down assays were performed to further explore the downstream potential molecular mechanisms.

Results

CircRNA_0000392 was significantly upregulated in CRC compared with normal adjacent tissues and cell lines. The expression level of circRNA_0000392 was positively correlated with the malignant progression of CRC. Functional studies revealed that reducing the expression of circRNA_0000392 could inhibit the proliferation and invasion of CRC both in vitro and in vivo. Mechanistically, circRNA_0000392 could act as a sponge of miR-193a-5p and regulate the expression of PIK3R3, affecting the activation of the AKT-mTOR pathway in CRC cells.

Conclusions

CircRNA_0000392 functions as an oncogene through the miR-193a-5p/PIK3R3/Akt axis in CRC cells, suggesting that circRNA_0000392 is a potential therapeutic target for the treatment of colorectal cancer and a predictive marker for CRC patients.

MicroRNA-1276 Promotes Colon Cancer Cell Proliferation by Negatively Regulating LACTB

Purpose

LACTB, regulated by a variety of microRNAs (miRNAs), is proven to be a tumor suppressor. However, there are few reports that LACTB in colon cancer cells is regulated by miRNA. Therefore, the aim of this study was to explore the miRNAs that regulate LACTB in colon cancer.

Patients and Methods

Data from TCGA were analyzed in starBase and GEPIA2, and Western blot and quantitative PCR (qPCR) were used to detect the expression of LACTB in colon cancer cell lines. MiRNAs targeting LACTB were predicted by MicroT-CDS, starBase, miRDB, mirDIP, and DIANA. The relationship between LACTB and miRNA was explored by dual-luciferase assay. MTT, propidium iodide (PI), Western blot, Annexin V-FITC/PI Kit, qPCR and transwell assay were used to detect the changes in cell proliferation, cell cycle, autophagy, apoptosis, epithelial-to-mesenchymal transition (EMT), cell migration, and invasiveness in colon cancer cells that overexpressed miR-1276 and/or LACTB.

Results

The results showed that the LACTB mRNA level was lower and the miR-1276 level was higher in colon cancer than in normal tissue. MiR-1276 inhibited the expression of LACTB. Furthermore, overexpression of miR-1276 in colon cancer cells increased proliferation, migration, invasiveness and EMT, and decreased autophagy and apoptosis. Supplementing LACTB suppressed these effects of miR-1276.

Conclusion

In conclusion, miR-1276, which may be a potential therapy for colon cancer, inhibits cell growth and promotes apoptosis by targeting LACTB in colon cancer cells.

Key factors mediated by PI3K signaling pathway and related genes in endometrial carcinoma

By analyzing the gene expression of endometrial carcinoma (EC) patients, the key factors in PI3K signaling pathway and its related genes mediating EC were explored. The EC samples and normal endometrial samples were downloaded from TCGA database and GTEx database. The R language "limma" package was used for differential analysis, and the expression level of genes in each tissue was analyzed by "gganatogram" package. Functional enrichment analysis of differential genes was carried out by KOBAS, an online bioinformatics website. The correlation between key genes and differential genes was evaluated using TCGA data and GTEx combined gene expression data. The corresponding clinical data were downloaded from TCGA database and GTEx database, and the R language "survival" package was used to assess the potential of candidate differential genes as a key factor of EC. Based on the combined differential analysis of TCGA and GTEx databases, 299 genes with significant differential in expression were finally got. Functional enrichment analysis revealed that genes were predominantly enriched in the entry of "Pathways in cancer", including RAC2 and PIK3R3 genes which were related with the abnormal PI3K pathway in cancer. PIK3R3, a key gene in the PI3K signaling pathway, was highly-expressed in EC. SPDEF, GCNT2, KIAA1324, C9orf152, MARVELD3, and APEX2 genes were found to be positively correlated with PIK3R3 in EC, all of which were highly expressed in EC. KM survival analysis showed that SPDEF, GCNT2, KIAA1324 and C9orf152 were significantly correlated with patients' survival. ROC analysis showed that SPDEF, GCNT2, KIAA1324 and C9orf152 gene could be used as potential markers for prognosis and survival of EC patients. It was found that PIK3R3, a key gene in the PI3K signaling pathway, was highly expressed in EC. The SPDEF, GCNT2, KIAA1324 and C9orf152 genes were also highly expressed in EC, and were positively correlated with PIK3R3 in EC. Moreover, they are significantly correlated with the patients' survival, suggesting that they may be potential markers for the prognosis of patients with EC.