The Potential Value of the PI3K/Akt/mTOR Signaling Pathway for Assessing Prognosis in Cervical Cancer and as a Target for Therapy

Regulation of cervical cancer via G15-mediated inhibition of G protein-coupled estrogen receptor

Cervical cancer is among the most common gynecological malignancies. G protein-coupled estrogen receptor (GPER) is involved in the development of various tumors; however, its role in cervical cancer remains unclear. We investigated whether G15, an inhibitor of GPER, can regulate its expression and affect cervical cancer progression. We examined the biological behaviors of G15-treated SiHa and HeLa cells using Cell Counting Kit-8, monoclonal proliferation, plate scratching, and Transwell invasion experiments. Western blotting was used to detect the expression of GPER, E-cadherin, N-cadherin, vimentin, Bcl-2, Bax, phosphatidylinositol-3-kinase (PI3K)/AKT, and programmed death ligand 1 (PD-L1). The expression of GPER, E-cadherin, vimentin, and PD-L1 in cervical cancer and adjacent tissues was detected using immunohistochemistry. The correlation between GPER expression and clinicopathological characteristics was analyzed. The expression of GPER in cervical cancer tissues was significantly higher than that in paracancerous tissues, and it was detected in the membrane and cytoplasm of SiHa and HeLa cells. The proliferation, migration, and invasion abilities of SiHa and HeLa cells were reduced after G15 treatment. The G15-treated groups exhibited higher expression of E-cadherin and Bax and lower expression of N-cadherin, vimentin, Bcl-2, GPER, p-PI3K, p-AKT, and PD-L1 than the control group. The expression of E-cadherin was lower and that of vimentin was higher in cancer tissues than in paracancerous tissues; PD-L1 was highly expressed in tumor and stromal cells in cancer tissues but not in paracancerous tissues. G15 functions by regulating the GPER/PI3K/AKT/PD-L1 signaling pathway and may serve as a new immunotherapy for treating patients with cervical cancer.

M2-type tumor-associated macrophages upregulated PD-L1 expression in cervical cancer via the PI3K/AKT pathway

BACKGROUND AND PURPOSE

PD-1/PD-L1 inhibitors have become a promising therapy. However, the response rate is lower than 30% in patients with cervical cancer (CC), which is related to immunosuppressive components in tumor microenvironment (TME). Tumor-associated macrophages (TAMs), as one of the most important immune cells, are involved in the formation of tumor suppressive microenvironment. Therefore, it will provide a theoretical basis for curative effect improvement about the regulatory mechanism of TAMs on PD-L1 expression.

METHODS

The clinical data and pathological tissues of CC patients were collected, and the expressions of PD-L1, CD68 and CD163 were detected by immunohistochemistry. Bioinformatics was used to analyze the macrophage subtypes involved in PD-L1 regulation. A co-culture model was established to observe the effects of TAMs on the morphology, migration and invasion function of CC cells, and the regulatory mechanism of TAMs on PD-L1.

RESULTS

PD-L1 expression on tumor cells could predict the poor prognosis of patients. And there was a strong correlation between PD-L1 expression with CD163+TAMs infiltration. Similarly, PD-L1 expression was associated with M1/M2-type TAMs infiltration in bioinformatics analysis. The results of cell co-culture showed that M1/M2-type TAMs could upregulate PD-L1 expression, especially M2-type TAMs may elevate the PD-L1 expression via PI3K/AKT pathway. Meanwhile, M1/M2-type TAMs can affect the morphological changes, and enhance migration and invasion abilities of CC cells.

CONCLUSIONS

PD-L1 expression in tumor cells can be used as a prognostic factor and is closely related to CD163+TAMs infiltration. In addition, M2-type TAMs can upregulate PD-L1 expression in CC cells through PI3K/AKT pathway, enhance the migration and invasion capabilities, and affect the tumor progression.

Exploiting new strategies in combating head and neck carcinoma: A comprehensive review on phytochemical approaches passing through PI3K/Akt/mTOR signaling pathway

Recently, malignant neoplasms have growingly caused human morbidity and mortality. Head and neck cancer (HNC) constitutes a substantial group of malignancies occurring in various anatomical regions of the head and neck, including lips, mouth, throat, larynx, nose, sinuses, oropharynx, hypopharynx, nasopharynx, and salivary glands. The present study addresses the phosphoinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) pathway as a possible therapeutic target in cancer therapy. Finding new multitargeting agents capable of modulating PI3K/Akt/mTOR and cross-linked mediators could be viewed as an effective strategy in combating HNC. Recent studies have introduced phytochemicals as multitargeting agents and rich sources for finding and developing new therapeutic agents. Phytochemicals have exhibited immense anticancer effects, including targeting different stages of HNC through the modulation of several signaling pathways. Moreover, phenolic/polyphenolic compounds, alkaloids, terpenes/terpenoids, and other secondary metabolites have demonstrated promising anticancer activities because of their diverse pharmacological and biological properties like antiproliferative, antineoplastic, antioxidant, and anti-inflammatory activities. The current review is mainly focused on new therapeutic strategies for HNC passing through the PI3K/Akt/mTOR pathway as new strategies in combating HNC.

Fabrication of bimetallic Ag@ZnO nanocomposite and its anti-cancer activity on cervical cancer via impeding PI3K/AKT/mTOR pathway

INTRODUCTION

Bimetallic nanoparticles, specifically Zinc oxide (ZnO) and Silver (Ag), continue to much outperform other nanoparticles investigated for a variety of biological uses in the field of cancer therapy. This study introduces biosynthesis of bimetallic silver/zinc oxide nanocomposites (Ag@ZnO NCs) using the Crocus sativus extract and evaluates their anti-cancer properties against cervical cancer.

METHODS

The process of generating bimetallic nanoparticles (NPs), namely Ag@ZnO NCs, through the utilization of Crocus sativus extract proved to be uncomplicated and eco-friendly. Various methods, such as UV-vis, DLS, FTIR, EDX, and SEM analyses, were utilized to characterize the generated Ag@ZnO NCs. The MTT assay was employed to assess the cytotoxic properties of biosynthesized bimetallic Ag@ZnO NCs against the HeLa cervical cancer cell line. Moreover, the impact of Ag@ZnO NCs on HeLa cells was assessed by examining cell survival, ROS production, MMP levels, and induced apoptosis. Through western blot analysis, the expression levels of the PI3K, AKT, mTOR, Cyclin D, and CDK proteins seemed to be ascertained. Using flow cytometry, the cancer cells' progression through necrosis and apoptosis, in addition to the cell cycle analysis, were investigated.

RESULTS

Bimetallic Ag@ZnO NCs that were biosynthesized showed a high degree of stability, as demonstrated by the physicochemical assessments. The median size of the particles in these NCs was approximately 80-90 nm, and their zeta potential was -14.70 mV. AgNPs and ZnO were found, according to EDX data. Further, Ag@ZnO NCs hold promise as a potential treatment for cervical cancer. After 24 hours of treatment, a dosage of 5 µg/mL or higher resulted in a maximum inhibitory effect of 58 ± 2.9. The concurrent application of Ag/ZnO NPs to HeLa cells resulted in elevated apoptotic signals and a significant generation of reactive oxygen species (ROS). As a result, the bimettalic Ag@ZnO NCs treatment has been recognized as a chemotherapeutic intervention by inhibiting the production of PI3K, AKT, and mTOR-mediated regulation of propagation and cell cycle-regulating proteins.

CONCLUSIONS

The research yielded important insights into the cytotoxic etiology of biosynthesized bimetallic Ag@ZnO NCs against HeLa cells. The biosynthesized bimetallic Ag@ZnO NCs have a significant antitumor potential, which appears to be associated with the development of oxidative stress, which inhibits the development of the cell cycle and the proliferation of cells. Therefore, in the future, biosynthesized bimetallic Ag@ZnO NCs may be used as a powerful anticancer drug to treat cervical cancer.

Design, synthesis, and biological evaluation of novel benzimidazole derivatives as anti-cervical cancer agents through PI3K/Akt/mTOR pathway and tubulin inhibition

Phosphatidylinositol 3-kinase (PI3K) is one of the most attractive therapeutic targets for cervical cancer treatment. In this study, we designed and synthesized a series of benzimidazole derivatives and evaluated their anti-cervical cancer activity. Compound 4r exhibited strong antiproliferative activity in different cervical cancer cell lines HeLa, SiHa and Ca Ski, and relative lower cytotoxicity to normal hepatic and renal cell lines LO2 and HEK-293t (IC50 values were at 21.08 μM and 23.96 μM respectively). Its IC50 value was at 3.38 μM to the SiHa cells. Further mechanistic studies revealed that 4r induced apoptosis, arrested cell cycle in G2/M phase, suppressed PI3K/Akt/mTOR pathway and inhibit the polymerization of tubulin. Molecular docking study suggested that 4r formed key H-bonds action with PI3Kα (PDB ID:8EXU) and tubulin (PDB ID:1SA0). Zebrafish acute toxicity experiments showed that high concentrations of 4r did not cause death or malformation of zebrafish embryos. All these results demonstrated that 4r would be a promising lead candidate for further development of novel PI3K and tubulin dual inhibitors in cervical cancer treatment.

Combination of Formononetin and Sulforaphane Natural Drug Repress the Proliferation of Cervical Cancer Cells via Impeding PI3K/AKT/mTOR Pathway

Natural substances have been demonstrated to be an unrivalled source of anticancer drugs in the present era of pharmacological development. Plant-based substances, together with their derivatives through analogues, play a significant character in the treatment of cancer by altering the tumor microenvironment and several signaling pathways. In this study, it was investigated whether the natural drugs, formononetin (FN) and sulforaphane (SFN), when combined, assess the efficacy of inhibiting cervical cancer cell proliferation by impeding the PI3K/Akt/mTOR signaling pathway in HeLa cells. The cells were treated with the combination of FN and SFN (FN + SFN) in various concentrations (0-50 µM) for 24 h and then analyzed for various experiments. The combination of FN + SFN-mediated cytotoxicity was analyzed by MTT assay. DCFH-DA staining was used to assess the ROS measurement, and apoptotic changes were studied by dual (AO/EtBr) staining assays. Protein expressions of cell survival, cell cycle, proliferation, and apoptosis protein were evaluated by flow cytometry and western blotting. Results showed that the cytotoxicity of FN and SFN was determined to be around 23.7 µM and 26.92 µM, respectively. Combining FN and SFN causes considerable cytotoxicity in HeLa cells, with an IC50 of 21.6 µM after 24-h incubation. Additionally, HeLa cells treated with FN and SFN together showed increased apoptotic signals and considerable ROS generation. Consequently, by preventing the production of PI3K, AKT, and mToR-mediated regulation of proliferation and cell cycle-regulating proteins, the combined use of FN + SFN has been regarded as a chemotherapeutic medication. Further research will need to be done shortly to determine how effectively the co-treatment promotes apoptosis to employ them economically.

The effects of HPV oncoproteins on host communication networks: Therapeutic connotations

Human papillomavirus (HPV) infections are a leading cause of viral-induced malignancies worldwide, with a prominent association with cervical and head and neck cancers. The pivotal role of HPV oncoproteins, E5, E6, and E7, in manipulating cellular events, which contribute to viral pathogenesis in various ways, has been extensively documented. This article reviews the influence of HPV oncoproteins on cellular signaling pathways within the host cell, shedding light on the underlying molecular mechanisms. A comprehensive understanding of these molecular alterations is essential for the development of targeted therapies and strategies to combat HPV-induced premalignancies and prevent their progress to cancer. Furthermore, this review underscores the intricate interplay between HPV oncoproteins and some of the most important cellular signaling pathways: Notch, Wnt/β-catenin, MAPK, JAK/STAT, and PI3K AKT/mTOR. The treatment efficacies of the currently available inhibitors on these pathways in an HPV-positive context are also discussed. This review also highlights the importance of continued research to advance our knowledge and enhance therapeutic interventions for HPV-associated diseases.

Regulation of Eukaryotic Translation Initiation Factor 4E as a Potential Anticancer Strategy

Eukaryotic translation initiation factors (eIFs) are highly expressed in cancer cells, especially eIF4E, the central regulatory node driving cancer cell growth and a potential target for anticancer drugs. eIF4E-targeting strategies primarily focus on inhibiting eIF4E synthesis, interfering with eIF4E/eIF4G interactions, and targeting eIF4E phosphorylation and peptide inhibitors. Although some small-molecule inhibitors are in clinical trials, no eIF4E inhibitors are available for clinical use. We provide an overview of the regulatory mechanisms of eIF4E and summarize the progress in developing and discovering eIF4E inhibitor strategies. We propose that interference with eIF4E/eIF4G interactions will provide a new perspective for the design of eIF4E inhibitors and may be a preferred strategy.

CRTAC1 enhances the chemosensitivity of non-small cell lung cancer to cisplatin by eliciting RyR-mediated calcium release and inhibiting Akt1 expression

Sensitivity to platinum-based combination chemotherapy is associated with a favorable prognosis in patients with non-small cell lung cancer (NSCLC). Here, our results obtained from analyses of the Gene Expression Omnibus database of NSCLC patients showed that cartilage acidic protein 1 (CRTAC1) plays a role in the response to platinum-based chemotherapy. Overexpression of CRTAC1 increased sensitivity to cisplatin in vitro, whereas knockdown of CRTAC1 decreased chemosensitivity of NSCLC cells. In vivo mouse experiments showed that CRTAC1 overexpression increased the antitumor effects of cisplatin. CRTAC1 overexpression promoted NFAT transcriptional activation by increasing intracellular Ca2+ levels, thereby inducing its regulated STUB1 mRNA transcription and protein expression, accelerating Akt1 protein degradation and, in turn, enhancing cisplatin-induced apoptosis. Taken together, the present results indicate that CRTAC1 overexpression increases the chemosensitivity of NSCLC to cisplatin treatment by inducing Ca2+-dependent Akt1 degradation and apoptosis, suggesting the potential of CRTAC1 as a biomarker for predicting cisplatin chemosensitivity. Our results further reveal that modulating the expression of CRTAC1 could be a new strategy for increasing the efficacy of cisplatin in chemotherapy of NSCLC patients.

MicroRNA-21 in gynecological cancers: From molecular pathogenesis to clinical significance

Ovarian, cervical, and endometrial cancers are the three most common gynecological cancer types (GCs). They hold a significant position as the leading causes of mortality among women with cancer-related death. However, GCs are often diagnosed late, severely limiting the efficacy of current treatment options. Thus, there is an urgent, unmet need for innovative experimentation to enhance the clinical treatment of GC patients. MicroRNAs (miRNAs) are a large and varied class of short noncoding RNAs (22 nucleotides in length) that have been shown to play essential roles in various biological processes involved in development. Recent research has shown that miR-211 influences tumorigenesis and cancer formation, adding to our knowledge of the miR-21 dysregulation in GCs. Furthermore, current research that sheds light on the crucial functions of miR-21 may provide supporting evidence for its potential prognostic, diagnostic, and therapeutic applications in the context of GCs. This review will thus focus on the most recent findings concerning miR-21 expression, miR-21 target genes, and the processes behind GCs. In addition, the latest findings that support miR-21's potential use as a non-invasive biomarker and therapeutic agent for detecting and treating cancer will be elucidated in this review. The roles played by various lncRNA/circRNA-miRNA-mRNA axis in GCs are also comprehensively summarized and described in this study, along with any possible implications for how these regulatory networks may contribute to the pathogenesis of GCs. Also, it is crucial to recognize the complexity of the processes involved in tumour therapeutic resistance as a significant obstacle in treating GCs. Furthermore, this review provides an overview of the current state of knowledge regarding the functional significance miR-21 in therapeutic resistance within the context of GCs.

Comprehensive analysis of lncRNA-mRNA co-expression networks in HPV-driven cervical cancer reveals the pivotal function of LINC00511-PGK1 in tumorigenesis

BACKGROUND

Mounting evidence suggests that noncoding RNAs (lncRNAs) were involved in various human cancers. However, the role of these lncRNAs in HPV-driven cervical cancer (CC) has not been extensively studied. Considering that HR-HPV infections contribute to cervical carcinogenesis by regulating the expression of lncRNAs, miRNAs and mRNAs, we aim to systematically analyze lncRNAs and mRNAs expression profile to identify novel lncRNAs-mRNAs co-expression networks and explore their potential impact on tumorigenesis in HPV-driven CC.

METHODS

LncRNA/mRNA microarray technology was utilized to identify the differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) in HPV-16 and HPV-18 cervical carcinogenesis compared to normal cervical tissues. Venn diagram and weighted gene co-expression network analysis (WGCNA) were used to identify the hub DElncRNAs/DEmRNAs that were both significantly correlated with HPV-16 and HPV-18 CC patients. LncRNA-mRNA correlation analysis and functional enrichment pathway analysis were performed on these key DElncRNAs/DEmRNAs in HPV-16 and HPV-18 CC patients to explore their mutual mechanism in HPV-driven CC. A lncRNA-mRNA co-expression score (CES) model was established and validated by using the Cox regression method. Afterward, the clinicopathological characteristics were analyzed between CES-high and CES-low groups. In vitro, functional experiments were performed to evaluate the role of LINC00511 and PGK1 in cell proliferation, migration and invasion in CC cells. To understand whether LINC00511 play as an oncogenic role partially via modulating the expression of PGK1, rescue assays were used.

RESULTS

We identified 81 lncRNAs and 211 mRNAs that were commonly differentially expressed in HPV-16 and HPV-18 CC tissues compared to normal tissues. The results of lncRNA-mRNA correlation analysis and functional enrichment pathway analysis showed that the LINC00511-PGK1 co-expression network may make an important contribution to HPV-mediated tumorigenesis and be closely associated with metabolism-related mechanisms. Combined with clinical survival data, the prognostic lncRNA-mRNA co-expression score (CES) model based on LINC00511 and PGK1 could precisely predict patients' overall survival (OS). CES-high patients had a worse prognosis than CES-low patients and the enriched pathways and potential targets of applicable drugs were explored in CES-high patients. In vitro experiments confirmed the oncogenic functions of LINC00511 and PGK1 in the progression of CC, and revealed that LINC00511 functions in an oncogenic role in CC cells partially via modulating the expression of PGK1.

CONCLUSIONS

Together, these data identify co-expression modules that provide valuable information to understand the pathogenesis of HPV-mediated tumorigenesis, which highlights the pivotal function of the LINC00511-PGK1 co-expression network in cervical carcinogenesis. Furthermore, our CES model has a reliable predicting ability that could stratify CC patients into low- and high-risk groups of poor survival. This study provides a bioinformatics method to screen prognostic biomarkers which leads to lncRNA-mRNA co-expression network identification and construction for patients' survival prediction and potential drug applications in other cancers.

Protein Profiling in Human Papillomavirus-Associated Cervical Carcinogenesis: Cornulin as a Biomarker for Disease Progression

Nearly 90% of cervical cancers are linked to human papillomavirus (HPV). Uncovering the protein signatures in each histological phase of cervical oncogenesis provides a path to biomarker discovery. The proteomes extracted from formalin-fixed paraffin-embedded tissues of the normal cervix, HPV16/18-associated squamous intraepithelial lesion (SIL), and squamous cell carcinoma (SCC) were compared using liquid chromatography-mass spectrometry (LC-MS). A total of 3597 proteins were identified, with 589, 550, and 1570 proteins unique to the normal cervix, SIL, and SCC groups, respectively, while 332 proteins overlapped between the three groups. In the transition from normal cervix to SIL, all 39 differentially expressed proteins were downregulated, while all 51 proteins discovered were upregulated in SIL to SCC. The binding process was the top molecular function, while chromatin silencing in the SIL vs. normal group, and nucleosome assembly in SCC vs. SIL groups was the top biological process. The PI3 kinase pathway appears crucial in initiating neoplastic transformation, while viral carcinogenesis and necroptosis are important for cell proliferation, migration, and metastasis in cervical cancer development. Annexin A2 and cornulin were selected for validation based on LC-MS results. The former was downregulated in the SIL vs. normal cervix and upregulated in the progression from SIL to SCC. In contrast, cornulin exhibited the highest expression in the normal cervix and lowest in SCC. Although other proteins, such as histones, collagen, and vimentin, were differentially expressed, their ubiquitous expression in most cells precluded further analysis. Immunohistochemical analysis of tissue microarrays found no significant difference in Annexin A2 expression between the groups. Conversely, cornulin exhibited the strongest expression in the normal cervix and lowest in SCC, supporting its role as a tumor suppressor and potential biomarker for disease progression.

Molecular mechanisms augmenting resistance to current therapies in clinics among cervical cancer patients

Cervical cancer (CC) is the fourth leading cause of cancer death (~ 324,000 deaths annually) among women internationally, with 85% of these deaths reported in developing regions, particularly sub-Saharan Africa and Southeast Asia. Human papillomavirus (HPV) is considered the major driver of CC, and with the availability of the prophylactic vaccine, HPV-associated CC is expected to be eliminated soon. However, female patients with advanced-stage cervical cancer demonstrated a high recurrence rate (50-70%) within two years of completing radiochemotherapy. Currently, 90% of failures in chemotherapy are during the invasion and metastasis of cancers related to drug resistance. Although molecular target therapies have shown promising results in the lab, they have had little success in patients due to the tumor heterogeneity fueling resistance to these therapies and bypass the targeted signaling pathway. The last two decades have seen the emergence of immunotherapy, especially immune checkpoint blockade (ICB) therapies, as an effective treatment against metastatic tumors. Unfortunately, only a small subgroup of patients (< 20%) have benefited from this approach, reflecting disease heterogeneity and manifestation with primary or acquired resistance over time. Thus, understanding the mechanisms driving drug resistance in CC could significantly improve the quality of medical care for cancer patients and steer them to accurate, individualized treatment. The rise of artificial intelligence and machine learning has also been a pivotal factor in cancer drug discovery. With the advancement in such technology, cervical cancer screening and diagnosis are expected to become easier. This review will systematically discuss the different tumor-intrinsic and extrinsic mechanisms CC cells to adapt to resist current treatments and scheme novel strategies to overcome cancer drug resistance.

ERBB3 mediates the PI3K/AKT/mTOR pathway to alter the epithelial‑mesenchymal transition in cervical cancer and predict immunity filtration outcome

Cervical cancer is the fourth most common cancer among women worldwide, and the prognosis of advanced/recurrent cervical cancer remains poor. Metastasis and invasion of this type of cancer are closely associated with the tumor microenvironment. Studying the complex interactions between tumor progression and immune cells or stromal cells can provide new insights into treatment for patients with aggressive tumor, recurrence and drug resistance. In the present study, a bioinformatics method (Gene Expression Profiling Interactive Analysis, differentially expressed genes, Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, protein-protein interactions and survival analysis) was used to explore the mRNA and protein level discrepancy gene signature of ERBB3 via the PI3K/AKT/mTOR pathway from the speculation in immuno-oncology and experimental verification of different cervical cancer cell lines. The high expression of ERBB3 in cervical cancer tissues (especially HPV-positive and adenocarcinoma-related) promoted the activation of the PI3K/AKT/mTOR pathway. The increased expression of MMP9 changed the macrophage infiltration in the tumor microenvironment and affected prognosis of patients with cervical cancer. In conclusion, the present study identified 14 EMT-related genes and 30 genes involved in the PI3K/AKT/mTOR pathway in cervical cancer, and they might provide novel clues for future treatment. The MMP family may be a notable factor associated with tumor cells and immune cells.

Up-regulation of long non-coding RNA LOXL1-AS1 functions as an oncogene in cervical squamous cell carcinoma by sponging miR-21

LncRNA LOXL1-AS1 has been reported to be upregulated in several types of cancer and plays oncogenic roles. We analysed TCGA dataset and observed the downregulation of LOXL1-AS1 in cervical squamous cell carcinoma (CSCC). We therefore analysed the roles of LOXL1-AS1 in CSCC. We observed that LOXL1-AS1 was downregulated in CSCC. LOXL1-AS1 was predicted to interact with miR-21, while overexpression experiments showed that LOXL1-AS1 and miR-21 had no significant effects on the expression of each other. However, LOXL1-AS1 overexpression led to the upregulation of RHOB, a direct target of miR-21. Cell invasion and migration analysis showed decreased invasion and migration rates of CSCC cells after LOXL1-AS1 and RHOB overexpression. MiR-21 played an opposite role at reduced the effects of LOXL1-AS1 and RHOB overexpression. Therefore, LOXL1-AS1 may promote CSCC cell invasion and migration by sponging miR-21 to upregulate RHOB.

Anticancer Effect of Pomegranate Peel Polyphenols against Cervical Cancer

Polyphenols are a broad group of bioactive phytochemicals with powerful antioxidant, anti-inflammatory, immunomodulatory, and antiviral activities. Numerous studies have demonstrated that polyphenol extracts obtained from natural sources can be used for the prevention and treatment of cancer. Pomegranate peel extract is an excellent source of polyphenols, such as punicalagin, punicalin, ellagic acid, and caffeic acid, among others. These phenolic compounds have antineoplastic activity in in vitro models of cervical cancer through the regulation of cellular redox balance, induction of apoptosis, cell cycle arrest, and modulation of different signaling pathways. The current review summarizes recent data from scientific reports that address the anticancer activity of the predominant polyphenol compounds present in PPE and their different mechanisms of action in cervical cancer models.

ECT2 promotes malignant phenotypes through the activation of the AKT/mTOR pathway and cisplatin resistance in cervical cancer

Epithelial cell transforming sequence 2 (ECT2) is expressed at high levels in various malignancies and contributes to malignant phenotypes in cancers. However, ECT2 is still not fully understood regarding its function and carcinogenic mechanism in cervical cancer. This research indicated that ECT2 expression was elevated in cervical cancer based on bioinformatics analysis and clinical specimens. Experiments in vitro and in vivo confirmed that ECT2 knockdown could suppress the proliferation and metastasis of cervical carcinoma cells. In addition, we found that silencing ECT2 could enhance the sensitivity to cisplatin and promote cell apoptosis. Mechanistically, we observed that ECT2 knockdown could inhibit the AKT/mTOR pathway and activate apoptosis, while ECT2 overexpression induced the opposite effect. The relationship between ECT2 and AKT was further confirmed by immunoprecipitation and rescue experiments. We found that the ECT2 and AKT could interact to form a complex, and knockdown AKT could offset all of the effects induced by ECT2. Our study emphasized the key point of ECT2 in the reversal of cisplatin resistance, and ECT2 could become a potential therapeutic target in cervical cancer.

RNA N6-methyladenosine modification mediates downregulation of NR4A1 to facilitate malignancy of cervical cancer

BACKGROUND

N⁶-methyladenosine is the most abundant eukaryotic mRNA modification and alters a wide range of cellular processes in cancer. Therefore, defining the molecular details are critical for understanding the regulatory mechanism of m⁶A modification.

RESULTS

We found that METTL3, a core m⁶A methyltransferase component, is upregulated and functions as an oncogene in cervical cancer. Mechanistically, METTL3 induces the degradation of m⁶A-modified transcripts of NR4A1 though YTHDF2-DDX6 pathway. In addition, NR4A1 overexpression attenuates the malignant progression through recruiting the LSD1/HDAC1/CoREST transcriptional repression complex to AKT1 promoter.

CONCLUSIONS

Our findings reveal that m⁶A regulates cervical cancer cellular progression through manipulating NR4A1 pathway.

Prediction of Cervical Cancer Outcome by Identifying and Validating a NAD+ Metabolism-Derived Gene Signature

Cervical cancer (CC) is the second most common female cancer. Excellent clinical outcomes have been achieved with current screening tests and medical treatments in the early stages, while the advanced stage has a poor prognosis. Nicotinamide adenine dinucleotide (NAD+) metabolism is implicated in cancer development and has been enhanced as a new therapeutic concept for cancer treatment. This study set out to identify an NAD+ metabolic-related gene signature for the prospect of cervical cancer survival and prognosis. Tissue profiles and clinical characteristics of 293 cervical cancer patients and normal tissues were downloaded from The Cancer Genome Atlas database to obtain NAD+ metabolic-related genes. Based on the differentially expressed NAD+ metabolic-related genes, cervical cancer patients were divided into two subgroups (Clusters 1 and 2) using consensus clustering. In total, 1404 differential genes were acquired from the clinical data of these two subgroups. From the NAD+ metabolic-related genes, 21 candidate NAD+ metabolic-related genes (ADAMTS10, ANGPTL5, APCDD1L, CCDC85A, CGREF1, CHRDL2, CRP, DENND5B, EFS, FGF8, P4HA3, PCDH20, PCDHAC2, RASGRF2, S100P, SLC19A3, SLC6A14, TESC, TFPI, TNMD, ZNF229) were considered independent indicators of cervical cancer prognosis through univariate and multivariate Cox regression analyses. The 21-gene signature was significantly different between the low- and high-risk groups in the training and validation datasets. Our work revealed the promising clinical prediction value of NAD+ metabolic-related genes in cervical cancer.

Artemin Promotes the Migration and Invasion of Cervical Cancer Cells through AKT/mTORC1 Signaling

Background. The neurotrophic factor Artemin (ARTN) is involved in tumor proliferation and metastasis. Nonetheless, ARTN’s significance in cervical cancer (CC) has not been studied. In our study, we propose to investigate the biological function of ARTN in CC as well as its particular regulatory mechanism. Methods. Immunohistochemistry (IHC) was used to examine the degree of ARTN protein expression in CC patient tissue. Real-time PCR and Western blotting were performed to reveal related genes’ levels in CC cells. The CCK-8 test, the colony formation assay, the wound-healing assay, and the transwell assay were utilized to determine the proliferation, migration, and invasion capabilities, respectively. To generate lung metastasis models, stable ARTN-expressing SiHa cells were injected into the caudal tail vein of mice. IHC was used to examine the protein levels in CC mice model tissues. Results. ARTN was overexpressed in CC tissues relative to normal cervical tissues and linked positively with lymph node metastases ( $P=0.012$ ) and recurrence ( $P=0.015$ ) in CC patients. In vitro, ARTN overexpression promoted the proliferation, invasion, and migration of CC cells. In contrast, the consequences of depleting endogenous ARTN were the opposite. Moreover, overexpression of ARTN increased lung metastasis of CC cells in vivo and shortened the lifespan of mice models. In addition, ARTN overexpression significantly enhanced AKT phosphorylation on Ser473 and mTOR phosphorylation on Ser2448 and promoted the epithelial-mesenchymal transition (EMT) cascade. In addition, rapamycin, a selective inhibitor of mTORC1, might rescue the EMT phenotype caused by ARTN. Conclusion. Our findings suggested that ARTN may enhance CC metastasis through the AKT/mTORC1 pathway. ARTN is anticipated to be a novel potential therapeutic target for the treatment of CC metastases.

Prognostic Value of GPNMB, EGFR, p-PI3K, and Ki-67 in Patients with Esophageal Squamous Cell Carcinoma

Background. GPNMB is a newly discovered tumour-promoting factor that may promote tumour cell progression by activating the PI3K/AKT pathway by EGFR. However, there are insufficient studies about GPNMB in ESCC. This study investigated the relationship between GPNMB and EGFR/PI3K pathway genes in ESCC. Methods. The expression levels of GPNMB, EGFR, p-PI3K, and Ki-67 were examined using immunohistochemistry. Statistical analysis was done by SPSS 22.0 and R. Results. GPNMB mRNA expression is higher in ESCC compared with paracancerous tissues. The expression of EGFR, PIK3CA, PIK3CB, and AKT1 was increased in GPNMB upregulated samples. GPNMB expression was positively correlated with EGFR, p-PI3K, and Ki-67 expression. GPNMB was expressed higher in the AJCC III stage, lymph node metastasis, and moderately poorly differentiated patients. EGFR was higher expressed in patients with vascular invasion; p-PI3K expression in Kazak was higher than that in Han; Ki-67 expression was higher in $\text{tumour}\text{size}\ge 3\text{cm}$ . Patients with high expression of GPNMB, p-PI3K, and Ki-67 had worse OS. p-PI3K, Ki-67, nerve invasion, and lymphatic metastasis were independent risk factors, and postoperative adjuvant therapy was a protective factor in ESCC. Conclusion. As a tumour-promoting factor, GPNMB is expected to be a potential target for ESCC.

Role of Phosphatidylinositol 3-Kinase and Its Catalytic Unit PIK3CA in Cervical Cancer: A Mini-Review

In complicated disorders like cancer, signaling pathways form a tangled network. Targeting one gene may result in an unfavorable reaction from another off-target gene. Such entwined complexities may result in treatment resistance or failure in cancer patients. The PI3K/Akt/mTOR (phosphoinositol 3-kinase/protein kinase B/mammalian target of rapamycin) pathway is dysregulated in cervical cancer and is used as a biomarker for therapy. PI3K is a kinase that consists of a regulatory and catalytic domain and has phosphorylation capability. Class I components like the catalytic part (PIK3CA and PIK3CD) and regulatory part (like PIK3R1, PIK3R2, PIK3R3, and PIK3R5) are associated with oncogenesis and growth factors in cervical cancer. This review is aimed at discussing the involvement of the PI3K component of the PI3K/Akt/mTOR network in cervical cancer. Specifically, class I catalytic subunit PIK3CA has been identified as a pharmacological target, making it therapeutically significant. Apart from discussing the function of PI3K and PIK3CA in cervical cancer, we also discuss their inhibitors, which may be beneficial in treating cervical cancer.

In vitro assessment of roles of PPP1R14B in cervical and endometrial cancer

Cervical and endometrial cancers are common gynecologic cancers. Protein phosphatase 1 regulatory subunit 14B (PPP1R14B) is aberrantly expressed in several tumors, while its functions in cervical and endometrial cancers remain largely uncertain. The differentially expression of PPP1R14B in cervical and endometrial cancers was predicted by GEPIA2 and Human Protein Atlas databases. The diagnostic value was analyzed by AUC curve. The association between PPP1R14B expression and overall survival was predicted using Kaplan-Meier Plotter database. The function of PPP1R14B was investigated according to in vitro assessment. PPP1R14B and phosphorylation level of Akt were analyzed through western blotting. Cell proliferation was investigated by CCK-8 and EdU staining assays. Cell apoptosis was evaluated via TUNEL staining and caspase-3 activity assays. PPP1R14B level was upregulated in cervical and endometrial cancers, and it was associated with diagnosis and worse prognosis. PPP1R14B silencing constrained cell proliferation and promoted cell death in cervical and endometrial cancers cells. PPP1R14B knockdown suppressed activation of the Akt pathway. Re-activation of the Akt signaling reversed the anti-proliferative and cell death-promoting roles of PP1R14B knockdown in cervical and endometrial cancers cells. In conclusion, PPP1R14B knockdown represses cell proliferation and facilitates cell death by inhibiting the activation of the Akt signaling in cervical and endometrial cancers.

FASN promotes lymph node metastasis in cervical cancer via cholesterol reprogramming and lymphangiogenesis

Cervical cancer (CC) patients with lymph node metastasis (LNM) have a poor prognosis. Clarification of the detailed mechanisms underlying LNM may provide potential clinical therapeutic targets for CC patients with LNM. However, the molecular mechanism of LNM in CC is unclear. In the present study, we demonstrated that fatty acid synthase (FASN), one of the key enzymes in lipid metabolism, had upregulated expression in the CC samples and was correlated with LNM. Moreover, multivariate Cox proportional hazards analysis identified FASN as an independent prognostic factor of CC patients. Furthermore, gain-of-function and loss-of-function approaches showed that FASN promoted CC cell migration, invasion, and lymphangiogenesis. Mechanistically, on the one hand, FASN could regulate cholesterol reprogramming and then activate the lipid raft-related c-Src/AKT/FAK signaling pathway, leading to enhanced cell migration and invasion. On the other hand, FASN induced lymphangiogenesis by secreting PDGF-AA/IGFBP3. More importantly, knockdown of FASN with FASN shRNA or the inhibitors C75 and Cerulenin dramatically diminished LNM in vivo, suggesting that FASN plays an essential role in LNM of CC and the clinical application potential of FASN inhibitors. Taken together, our findings uncover a novel molecular mechanism in LNM of CC and identify FASN as a novel prognostic factor and potential therapeutic target for LNM in CC.

The clinical value of miRNA-21 in cervical cancer: A comprehensive investigation based on microarray datasets

Previous work has demonstrated that the expression of microRNA-21 (miR-21) is implicated in cervical cancer (CC). However, little is known regarding its associations with clinical parameters. We first conducted a meta-analysis using data from Gene Expression Omnibus (GEO) microarrays and The Cancer Genome Atlas (TCGA). Then, enrichment analysis and hub gene screening were performed by bioinformatic methods. Finally, the role of the screened target genes in CC was explored. According to the meta-analysis, the expression of miR-21 in cancer tissues was higher than in adjacent nontumor tissues (P < 0.05). In addition, 46 genes were predicted as potential targets of miR-21. After enrichment analyses, it was detected that these genes were enriched in various cancer pathways, including the phosphatidylinositol signaling system and mammalian target of rapamycin (mTOR) signaling pathway. In this study, bioinformatic tools and meta-analysis validated that miR-21 may function as a highly sensitive and specific marker for the diagnosis of CC, which may provide a novel approach to the diagnosis and treatment of CC.

Ox-LDL-mediated ILF3 overexpression in gastric cancer progression by activating the PI3K/AKT/mTOR signaling pathway

Background: This study aimed to investigate the relationship of dyslipidemia and interleukin-enhancer binding factor 3 (ILF3) in gastric cancer, and provide insights into the potential application of statins as an agent to prevent and treat gastric cancer.

Methods: The expression levels of ILF3 in gastric cancer were examined with publicly available datasets such as TCGA, and western blotting and immunohistochemistry were performed to determine the expression of ILF3 in clinical specimens. The effects of ox-LDL on expression of ILF3 were further verified with western blot analyses. RNA sequencing, Kyoto Encyclopedia of Genes and Genomes (KEGG), Gene Ontology (GO), and Gene Set Enrichment Analysis (GSEA) pathway analyses were performed to reveal the potential downstream signaling pathway targets of ILF3. The effects of statins and ILF3 on PI3K/AKT/mTOR signaling pathway, cell proliferation, cell cycle, migration and invasion of gastric cancer cells were investigated with Edu assay, flow cytometry and transwell assay.

Results: Immunohistochemistry and western blot demonstrated that the positive expression rates of ILF3 in gastric cancer tissues were higher than adjacent mucosa tissues. The ox-LDL promoted the expression of ILF3 in a time-concentration-dependent manner. ILF3 promoted the proliferation, cell cycle, migration and invasion by activating the PI3K/AKT/mTOR signaling pathway. Statins inhibited the proliferation, cell cycle, migration and invasion of gastric cancer by inhibiting the expression of ILF3.

Conclusions: These findings demonstrate that ox-LDL promotes ILF3 overexpression to regulate gastric cancer progression by activating the PI3K/AKT/mTOR signaling pathway. Statins inhibits the expression of ILF3, which might be a new targeted therapy for gastric cancer.

Everolimus (RAD001) combined with programmed death-1 (PD-1) blockade enhances radiosensitivity of cervical cancer and programmed death-ligand 1 (PD-L1) expression by blocking the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR)/S6 kinase 1 (S6K1) pathway

Cervical cancer (CC) is the 4^th most prevalent malignancy in females. This study explored the mechanism of everolimus (RAD001) combined with programmed death-1 (PD-1) blockade on radiosensitivity by phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway and autophagy in CC cells. Low-radiosensitive CaSki cells were selected as study objects. After RAD001 treatment, PI3K/AKT/mTOR pathway activation, autophagy, migration and invasion abilities, autophagy-related proteins (LC3-I, LC3-II, and p62), and PD-L1 expression in CC cells were detected. After triple treatment of radiotherapy (RT), RAD001, and PD-1 blockade to the CC mouse models, tumor weight and volume were recorded. Ki67 expression, the number of CD8 + T cells, and the ability to produce IFN-γ and TNF-α in tumor tissues were determined. RAD001 promoted autophagy by repressing PI3K/AKT/mTOR pathway, augmented RT-induced apoptosis, and weakened migration and invasion, thereby increasing CC cell radiosensitivity. RAD001 elevated RT-induced PD-L1 level. RT combined with RAD001 and PD-1 blockade intensified the inhibitory effect of RT on tumor growth, reduced the amount of Ki67-positive cells, enhanced radiosensitivity of CC mice, and increased the quantity and killing ability of CD8 + T cells. Briefly, RAD001 combined with PD-1 blockade increases radiosensitivity of CC by impeding the PI3K/AKT/mTOR pathway and potentiating cell autophagy.

Gene Promoter-Methylation Signature as Biomarker to Predict Cisplatin-Radiotherapy Sensitivity in Locally Advanced Cervical Cancer

Despite efforts to promote health policies focused on screening and early detection, cervical cancer continues to be one of the leading causes of mortality in women; in 2020, estimated 30,000 deaths in Latin America were reported for this type of tumor. While the therapies used to treat cervical cancer have excellent results in tumors identified in early stages, those women who are diagnosed in locally advanced and advanced stages show survival rates at 5 years of <50%. Molecular patterns associated with clinical response have been studied in patients who present resistance to treatment; none of them have reached clinical practice. It is therefore necessary to continue analyzing molecular patterns that allow us to identify patients at risk of developing resistance to conventional therapy. In this study, we analyzed the global methylation profile of 22 patients diagnosed with locally advanced cervical cancer and validated the genomic results in an independent cohort of 70 patients. We showed that BRD9 promoter region methylation and CTU1 demethylation were associated with a higher overall survival (p = 0.06) and progression-free survival (p = 0.0001), whereas DOCK8 demethylation was associated with therapy-resistant patients and a lower overall survival and progression-free survival (p = 0.025 and p = 0.0001, respectively). Our results suggest that methylation of promoter regions in specific genes may provide molecular markers associated with response to treatment in cancer; further investigation is needed.

Association of a genetic variant in Interleukin-10 gene with increased risk and inflammation associated with cervical cancer

BACKGROUND

Cervical-cancer is among the most commonly diagnosed cancers in women, and infection with human papillomavirus (HPV) is associated with an increased risk of cervical cancer and altered serum concentrations of inflammatory cytokines. We have explored the association between a genetic variation in the Interleukin-10 (IL-10) gene (rs1800896) and cervical cancer risk and its relationship with tissue Interferon gamma (IFN-γ), Transforming growth factor beta (TGF-β), Tumor necrosis factor alpha (TNF-α) concentrations in women with cervical cancer.

METHODS

A total of 315 women with, or without cervical cancer, were recruited into the study. DNA was extracted from cervical cells, and genotyping was undertaken using Taq-man real-time PCR. The genotype frequency and allele distribution were analyzed together with their association with pathological data. The association of the rs1800896 gene variation with tissue levels of the inflammatory cytokines was also investigated.

RESULTS

Our data showed a significant association between the A allele of the rs1800896 gene variant and the presence of cervical cancer. In particular, patients with AG/AA genotypes had an increased risk of cervical cancer with an odds ratio of 1.929 (95% confidence interval [CI]: 0.879-4.23, P < 0.001) in a recessive model, compared with the GG genotype. Also, the tissue concentrations of IFN-γ, TGF-β, and TNF-α in cervical tissues were significantly higher in women with cervical cancer (P < 0.001) and were associated with the AA genotype.

CONCLUSION

We have found an association between the polymorphism rs1800896 in the IL-10 gene and an increased risk of cervical cancer as well as a higher level of tissue inflammatory cytokines. Further investigations are necessary on the value of emerging biomarkers for the risk stratification for the management of cervical cancer patients.

miR-186-3p attenuates the tumorigenesis of cervical cancer via targeting insulin-like growth factor 1 to suppress PI3K-Akt signaling pathway

miR-186-3p acts as a tumor suppressor in various cancers. This study aimed to explore the expression levels of miR-186-3p and its role in cervical cancer. We analyzed the effects of miR-186-3p and insulin-like growth factor 1 (IGF1) on the proliferation, invasion, and apoptosis of cervical cancer cells in vitro by regulating the PI3K/Akt signaling pathway. In cervical cancer tissues and cells, miR-186-3p was downregulated, and IGF1 was upregulated. In addition, miR-186-3p inhibited cell proliferation and invasion and enhanced apoptosis of cervical cancer cells. Moreover, our results showed that miR-186-3p inversely regulated the mRNA expression of IGF1 through direct contact. Knockdown of IGF1 reversed the results of miR-186-3p inhibitor in cervical cancer cells. In addition, the PI3K/Akt signaling pathway was activated by the miR-186-3p inhibitor, although partially arrested by IGF1 knockdown. The PI3K/Akt signaling pathway inhibitor suppressed miR-186-3p inhibitor-stimulated cell proliferation in cervical cancer. In conclusion, miR-186-3p inhibits tumorigenesis of cervical cancer by repressing IGF1, which inactivates the PI3K/Akt signaling pathway, implicating miR-186-3p as a potential new target for the treatment of cervical cancer.

Anticancer effects of root and beet leaf extracts (Beta vulgaris L.) in cervical cancer cells (HeLa)

Cervical cancer is the fourth leading cause of cancer mortality in women worldwide. Beetroot (Beta vulgaris L.) has bioactive compounds that can inhibit the progression of different types of cancer. To analyze the antiproliferative effects of beet leaf and root extracts, we performed MTT, clonogenic survival, cell cycle analysis, Annexin/PI labeling, and western blotting. Here, we report that 10 and 100 μg/ml of root and leaf extracts decreased cell viability and potentiated rapamycin and cisplatin effects while decreased the number of large colonies, especially at 10 μg/ml (293.6 of control vs. 200.0 of leaf extract, p = .0059; 138.6 of root extract, p = .0002). After 48 hr, 100 μg/ml of both extracts led to increased sub-G1 and G0/G1 populations. In accordance, 100 μg/ml of root extract induced early apoptosis (mean = 0.64 control vs. 1.56 root; p = .048) and decreased cell size (p < .0001). Both extracts decreased phosphorylation and expression of mechanistic Target of Rapamycin (mTOR) signaling, especially by inhibiting ribosomal protein S6 (S6) phosphorylation, increasing cleaved poly(ADP-ribose) polysomerase 1 (PARP1) and Bcl-2-like protein 11 (BIM), and decreasing cyclin D1 expression, which regulates cell cycle progression. Here, we demonstrate that beetroot and leaf extracts could be an efficient strategy against cervical cancer.

Chemoradiotherapy-induced increase in Th17 cell frequency in cervical cancer patients is associated with therapy resistance and early relapse

Cervical cancer therapy is still a major clinical challenge, as patients substantially differ in their response to standard treatments, including chemoradiotherapy (CRT). During cervical carcinogenesis, T-helper (Th)-17 cells accumulate in the peripheral blood and tumor tissues of cancer patients and are associated with poor prognosis. In this prospective study, we find increased Th17 frequencies in the blood of patients after chemoradiotherapy and a post-therapeutic ratio of Th17/CD4⁺ T cells > 8% was associated with early recurrence. Furthermore, Th17 cells promote resistance of cervical cancer cells toward CRT, which was dependent on the AKT signaling pathway. Consistently, patients with high Th17 frequencies in pretherapeutic biopsies exhibit lower response to primary CRT. This work reveals a key role of Th17 cells in CRT resistance and elevated Th17 frequencies in the blood after CRT correspond with early recurrence. Our results may help to explain individual treatment responses of cervical cancer patients and suggest evaluation of Th17 cells as a novel predictive biomarker for chemoradiotherapy responses and as a potential target for immunotherapy in cervical cancer.

Oncogenic role of ALX3 in cervical cancer cells through KDM2B-mediated histone demethylation of CDC25A

Background

Cell division cycle 25A (CDC25A) is a well-recognized regulator of cell cycle progression and is involved in cancer development. This work focused on the function of CDC25A in cervical cancer cell growth and the molecules involved.

Methods

A GEO dataset GSE63514 comprising data of cervical squamous cell carcinoma (CSCC) tissues was used to screen the aberrantly expressed genes in cervical cancer. The CDC25A expression in cancer and normal tissues was predicted in the GEPIA database and that in CSCC and normal cells was determined by RT-qPCR and western blot assays. Downregulation of CDC25A was introduced in CSCC cells to explore its function in cell growth and the cell cycle progression. The potential regulators of CDC25A activity and the possible involved signaling were explored.

Results

CDC25A was predicted to be overexpressed in CSCC, and high expression of CDC25A was observed in CSCC cells. Downregulation of CDC25A in ME180 and C33A cells reduced cell proliferation and blocked cell cycle progression, and it increased cell apoptosis. ALX3 was a positive regulator of CDC25A through transcription promotion. It recruited a histone demethylase, lysine demethylase 2B (KDM2B), to the CDC25A promoter, which enhanced CDC25A expression through demethylation of H3k4me3. Overexpression of ALX3 in cells blocked the inhibitory effects of CDC25A silencing. CDC25A was found as a positive regulator of the PI3K/Akt signaling pathway.

Conclusion

This study suggested that the ALX3 increased CDC25A expression through KDM2B-mediated demethylation of H3K4me3, which induced proliferation and cell cycle progression of cervical cancer cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08552-7.

Exosomes: Emerging modulators of signal transduction in colorectal cancer from molecular understanding to clinical application

Exosomes are small cell derived membrane nano-vesicles that carry various components including lipids, proteins and nucleic acids. There is accumulating evidence that exosomes have a role in tumorigenesis, tumor invasiveness and metastasis. Furthermore, oncogene mutation may influence exosome release from tumor cells. Exosomes may induce colorectal cancer by altering signaling cascades such as the Wnt/β-catenin and KRAS pathways that are involved in cell proliferation, apoptosis, dissemination, angiogenesis, and drug resistance. The aim of this review was to overview recent findings evaluating the association between tumor cells-derived exosomes and their content in modulating signaling pathways in colorectal cancer.

Effect of BRAF-mediated PI3K/Akt/mTOR pathway on biological characteristics and chemosensitivity of NSCLC A549/DDP cells

The present study aimed to explore the biological characteristics of non-small cell lung cancer (NSCLC) cells and the mechanism of chemosensitivity through the role of the PI3K/Akt/mTOR signaling pathway mediated by BRAF gene silencing. Following cell transfection and grouping, an MTT assay detected the activity of NSCLC cells, a scratch wound test assessed the migration ability, flow cytometry using PI staining detected the cell cycle phase, TUNEL and flow cytometry through Annexin V-PI staining assessed the apoptosis, and colony formation was used to detect the sensitivity of lung cancer cells to cisplatin chemotherapy. Furthermore, the relative expression levels of BRAF, PTEN, PI3K, mTOR mRNA were assessed by RT-qPCR, and the protein expression levels of BRAF, PTEN, PI3K, phosphorylated (p)-PI3K, Akt, p-Akt, mTOR, p-mTOR, cisplatin resistance-related enzymes ERCC1 and BRCA1, apoptotic proteins Bax and Bcl-2 were assessed by western blotting. Compared with the control group and NC group, there were differences in decreased BRAF mRNA expression levels in the small interfering (si)BRAF group and siBRAF + IGF-1 group (both P<0.05). In addition, compared with the control group, the siBRAF, NVP-BEZ235 and siBRAF + NVP-BEZ235 groups had significant decreased cell viability at 2–6 days, decreased migration ability, shortened proportion of S-phase cells, increased proportion of G₁/G₀-phase cells, increased apoptosis rate, decreased number of colony-forming cells, decreased mRNA expression of PI3K, Akt and mTOR, increased PTEN mRNA expression, decreased protein expression levels of PI3K, p-PI3K, Akt, p-Akt, mTOR, p-mTOR, ERCC1, BRCA1 and Bcl-2, and increased protein expression levels of PTEN and Bax (all P<0.05); and more obvious trends were revealed in the siBRAF + NVP-BEZ235 group (all P<0.05); whereas opposite results were detected in the siBRAF + IGF-1 group when compared with the siBRAF group and NVP-BEZ235 group (all P<0.05). Silencing of BRAF gene expression to inhibit the activation of the PI3K/Akt/mTOR signaling pathway exerted a synergistic effect decreasing cell viability, inhibiting the cell cycle and migration, increasing the apoptosis rate, decreasing the number of colony-forming cells and increasing chemosensitivity of NSCLC. Activation of the PI3K/Akt/mTOR signaling pathway may reverse the role of silencing of BRAF gene expression, providing a potential approach for improving the chemosensitivity of NSCLC. The present study for the first time, to the best of our knowledge, clarified the possible mechanism of NSCLC cell biological characteristic changes and chemosensitivity from the perspective of BRAF gene silencing and PI3K/Akt/mTOR signaling pathway activation, providing a potential reference for suppressing tumor aggravation and improving the therapeutic outcomes of NSCLC at the genetic level.

Profiling of circular RNAs and circTPCN/miR-634/mTOR regulatory pathway in cervical cancer

Circular RNAs (circRNAs) are highly stable forms of endogenous non-coding RNA molecules with diverse biological functions. Some of them have been demonstrated to play crucial roles in the initiation or development of cancers through regulation of gene expression. However, the profiles and the roles of circRNAs in tumorigenesis of cervical cancer remain largely unknown. In the current study, we investigated the expression profiles of circRNAs and their potential oncogenic mechanisms in cervical cancer. The expression patterns, obtained using a microarray assay, revealed a total of 192 differentially expressed circRNAs, of which 106 were upregulated and 86 were downregulated, in cervical cancer samples compared with normal cervical samples. The differential expression of circRNAs was validated using quantitative real-time polymerase chain reaction. Two circRNAs (circTPCN and circFAM185A) were confirmed to be significantly upregulated in cervical cancer samples, indicating that they represent potential biomarkers of cervical cancer. The role and the potential molecular mechanism of circTPCN in cervical cancer tumorigenesis were further investigated. Knockdown of circTPCN significantly suppressed proliferation, migration, and invasion and increased apoptosis of cervical cancer cells in vitro. Molecular analysis revealed that circTPCN acted as a sponge of miR-634 to enhance mTOR expression. Thus, the circTPCN/miR-634/mTOR regulatory pathway might be involved in cervical cancer tumorigenesis, and circTPCN is a potential therapeutic target in cervical cancer.

E6-mediated activation of JNK drives EGFR signalling to promote proliferation and viral oncoprotein expression in cervical cancer

Human papillomaviruses (HPV) are a major cause of malignancy worldwide, contributing to ~5% of all human cancers including almost all cases of cervical cancer and a growing number of ano-genital and oral cancers. HPV-induced malignancy is primarily driven by the viral oncogenes, E6 and E7, which manipulate host cellular pathways to increase cell proliferation and enhance cell survival, ultimately predisposing infected cells to malignant transformation. Consequently, a more detailed understanding of viral-host interactions in HPV-associated disease offers the potential to identify novel therapeutic targets. Here, we identify that the c-Jun N-terminal kinase (JNK) signalling pathway is activated in cervical disease and in cervical cancer. The HPV E6 oncogene induces JNK1/2 phosphorylation in a manner that requires the E6 PDZ binding motif. We show that blockade of JNK1/2 signalling using small molecule inhibitors, or knockdown of the canonical JNK substrate c-Jun, reduces cell proliferation and induces apoptosis in cervical cancer cells. We further demonstrate that this phenotype is at least partially driven by JNK-dependent activation of EGFR signalling via increased expression of EGFR and the EGFR ligands EGF and HB-EGF. JNK/c-Jun signalling promoted the invasive potential of cervical cancer cells and was required for the expression of the epithelial to mesenchymal transition (EMT)-associated transcription factor Slug and the mesenchymal marker Vimentin. Furthermore, JNK/c-Jun signalling is required for the constitutive expression of HPV E6 and E7, which are essential for cervical cancer cell growth and survival. Together, these data demonstrate a positive feedback loop between the EGFR signalling pathway and HPV E6/E7 expression, identifying a regulatory mechanism in which HPV drives EGFR signalling to promote proliferation, survival and EMT. Thus, our study has identified a novel therapeutic target that may be beneficial for the treatment of cervical cancer.

Cervical Cancer Immunotherapy: Facts and Hopes

It is a sad fact that despite being almost completely preventable through human papillomavirus (HPV) vaccination and screening, cervical cancer remains the fourth most common cancer to affect women worldwide. Persistent high-risk HPV (hrHPV) infection is the primary etiologic factor for cervical cancer. Upward of 70% of cases are driven by HPV types 16 and 18, with a dozen other hrHPVs associated with the remainder of cases. Current standard-of-care treatments include radiotherapy, chemotherapy, and/or surgical resection. However, they have significant side effects and limited efficacy against advanced disease. There are a few treatment options for recurrent or metastatic cases. Immunotherapy offers new hope, as demonstrated by the recent approval of programmed cell death protein 1-blocking antibody for recurrent or metastatic disease. This might be augmented by combination with antigen-specific immunotherapy approaches, such as vaccines or adoptive cell transfer, to enhance the host cellular immune response targeting HPV-positive cancer cells. As cervical cancer progresses, it can foster an immunosuppressive microenvironment and counteract host anticancer immunity. Thus, approaches to reverse suppressive immune environments and bolster effector T-cell functioning are likely to enhance the success of such cervical cancer immunotherapy. The success of nonspecific immunostimulants like imiquimod against genital warts also suggest the possibility of utilizing these immunotherapeutic strategies in cervical cancer prevention to treat precursor lesions (cervical intraepithelial neoplasia) and persistent hrHPV infections against which the licensed prophylactic HPV vaccines have no efficacy. Here, we review the progress and challenges in the development of immunotherapeutic approaches for the prevention and treatment of cervical cancer.

Ultrasound-Targeted Microbubble Destruction Enhances the Inhibitive Efficacy of miR-21 Silencing in HeLa Cells

BACKGROUND Previous studies have shown that miR-21 upregulation is related to the aggressive development of cervical cancer. Ultrasound-targeted microbubble destruction (UTMD) is a method that increases the absorption of targeted genes or drugs by cells. We focus on the role of UTMD-mediated miR-21 transfection in HeLa cells, a cervical cancer cell line. MATERIAL AND METHODS The effects of different ultrasound intensities on the transfection efficiency of miR-21-enhanced green fluorescent protein (EGFP) and miR-21 inhibitor-EGFP plasmids were determined by flow cytometry. The effects of UTMD-mediated miR-21 transfection on HeLa cell proliferation, apoptosis, migration, and invasion were measured by CCK-8, flow cytometry, wound healing experiments, and transwell migration assay, respectively. Western blot and real-time quantitative PCR were used to detect the expression of tumor-related genes. RESULTS When the ultrasound intensity was 1.5 W/cm², the miR-21 plasmid had the highest transfection efficiency. Exogenous miR-21 promoted cell proliferation, migration, and invasion, and inhibited cell apoptosis in HeLa cells. Treatment of cells with UTMD further enhanced the effects of miR-21-EGFP and miR-21 inhibitor-EGFP. In addition, miR-21 overexpression significantly increased the expression of p-Akt, Akt, Bcl-2, Wnt, ß-catenin, matrix metalloprotein-9 (MMP-9), and epidermal growth factor (EGFR) levels, and decreased Bax expression. The regulatory role of miR-21 inhibitor-EGFP was opposite to that of miR-21-EGFP. After UTMD, miR-21-EGFP and miR-21 inhibitor-EGFP had more significant regulatory effects on these genes. CONCLUSIONS Our research revealed that an ultrasound intensity of 1.5 W/cm² is the best parameter for miR-21 transfection. UTMD can enhance the biological function of miR-21 in HeLa cells, and alter the effect of miR-21 on apoptosis, metastasis, and phosphorylation genes.

Tomentosin inhibits cell proliferation and induces apoptosis in MOLT-4 leukemia cancer cells through the inhibition of mTOR/PI3K/Akt signaling pathway

Leukemia is amongst the cancers accountable for substantial mortality around the world. Tomentosin is a bioactive compound with a pharmacological significance, and its anticancer property against human leukemia MOLT-4 cell line has never been reported. Hence, the objective of this study was to explore the anticancer activity of tomentosin in MOLT-4 human leukemia cells. In the current investigation, the cytotoxic effects of tomentosin ensuing potent toxicity (IC₅₀ : 10 µM) in MOLT-4 cells after incubation at 24 h have been presented. Furthermore, tomentosin triggered intracellular reactive oxygen species production and showed the induction of intrinsic/mitochondrial pathways in treated MOLT-4 cells, revealing a significant cytotoxicity activity. Also, fluorescent microscopic studies using acridine orange/ethidium bromide and propidium iodide staining confirmed the occurrence of apoptosis in tomentosin-treated MOLT-4 cells. Quantitative reverse transcription polymerase chain reaction presented a negative regulation of cyclin D1 and BcL-2 expression and a positive regulated BAX and caspase-3 messenger RNA expression in tomentosin-treated MOLT-4 cells. Tomentosin further inhibited the inflammatory transcription factors such as nuclear factor κB (NF-κB), tumor necrosis factor α, interleukin 1β (IL-1β), and IL-6. Additionally, inhibition of the m-TOR/PI3K/AKT protein expression by tomentosin in MOLT-4 cells was confirmed. Overall, these findings lead to a conclusion that tomentosin induces apoptosis in MOLT-4 cells through caspase-facilitated proapoptotic pathway, and inhibition of the NF-κB-stimulated Bcl-2 facilitated the antiapoptotic pathway.

Research on Radiosensitivity of the Protein Kinase B Signaling Pathway in Cervical Cancer

The main characteristics of cervical cancer are abnormal and uncontrolled cell proliferation, and it regulates cell growth, differentiation, and cell death through genetic and epigenetic changes. This paper mainly discusses the radiosensitivity of the cervical cancer protein kinase B signaling pathway and discusses the specific mechanisms that affect the occurrence and development of cervical cancer. In addition, this paper studies the effect of transient transfection knocking down the expression of TRIP4 in cervical cancer cells on the expression of key proteins in related signaling pathways and explores the mechanism of its specific effects and finds the mechanism of TRIP4's effect on cervical cancer radiosensitivity. The findings of this study show for the first time that knocking down TRIP4 inhibits cell viability by inhibiting the P13K/AKT and MAPK/ERK pathways, and this corresponds to the first part of the experimental results, which show that knocking down TRIP4 inhibits colony formation and increases apoptosis in HeLa and SiHa cells. Moreover, simultaneous inhibition of TRIP4 and hTERT proteins can increase the radiosensitivity of cervical cancer cells. These findings indicate that the inhibition of TRIP4 may be a new type of treatment that selectively targets the P13K/AKT and MAPK/ERK pathways and hTERT pathways in cervical cancer cells and provides a therapeutic option for the treatment of cervical cancer.

Therapeutic applications and biological activities of bacterial bioactive extracts

Bacteria are rich in a wide variety of secondary metabolites, such as pigments, alkaloids, antibiotics, and others. These bioactive microbial products serve a great application in human and animal health. Their molecular diversity allows these natural products to possess several therapeutic attributes and biological functions. That's why the current natural drug industry focuses on uncovering all the possible ailments and diseases that could be combated by bacterial extracts and their secondary metabolites. In this paper, we review the major utilizations of bacterial natural products for the treatment of cancer, inflammatory diseases, allergies, autoimmune diseases, infections and other diseases that threaten public health. We also elaborate on the identified biological activities of bacterial secondary metabolites including antibacterial, antifungal, antiviral and antioxidant activities all of which are essential nowadays with the emergence of drug-resistant microbial pathogens. Throughout this review, we discuss the possible mechanisms of actions in which bacterial-derived biologically active molecular entities could possess healing properties to inspire the development of new therapeutic agents in academia and industry.

Local and Systemic STAT3 and p65 NF-KappaB Expression as Progression Markers and Functional Targets for Patients With Cervical Cancer

Cervical cancer, which main etiologic factor is Human Papillomavirus (HPV) infection, continues to be a burden for public health systems in developing countries. Our laboratory has been working with the hypothesis that signals generated in the tumor microenvironment can modulate local and systemic immune responses. In this context, it would be reasonable to think that tumors create pro-tumoral bias in immune cells, even before they are recruited to the tumor microenvironment. To understand if and how signaling started in the tumor microenvironment can influence cells within the tumor and systemically, we investigated the expression of key proteins in signaling pathways important for cell proliferation, viability, immune responses and tolerance. Besides, we used detection of specific phosphorylated residues, which are indicative of activation for Akt, CREB, p65 NFκB, and STAT3. Our findings included the observation of a significant STAT3 expression increase and p65 NFκB decrease in circulating leukocytes in correlation with lesion grade. In light of those observations, we started investigating the result of the inhibition of STAT3 in a tumor experimental model. STAT3 inhibition impaired tumor growth, increased anti-tumor T cell responses and decreased the accumulation of myeloid cells in the spleen. The concomitant inhibition of NFκB partially reversed these effects. This study indicates that STAT3 and NFκB are involved in immunomodulatory tumor effects and STAT3 inhibition could be considered as therapy for patients with cervical cancer.

St. John's Wort Suppresses Growth in Triple-Negative Breast Cancer Cell Line MDA-MB-231 by Inducing Prodeath Autophagy and Apoptosis

The rational regulation of programmed cell death by means of autophagy and apoptosis has been considered a potential treatment strategy for cancer. We demonstrated the inhibitory effect of St. John’s Wort (SJW) on growth in the triple-negative breast cancer (TNBC) cell line and xenografted mice and its target mechanism concerning autophagic and apoptotic cell death. SJW ethanol extract (SJWE) inhibited proliferation in a dose-dependent manner. SJWE treatment dramatically increased autophagy flux and apoptosis compared with the control. The autophagy inhibitor, 3-methyladenine (3-MA), reversed the SJWE-induced inhibition of cell proliferation and regulation of autophagy and apoptosis, indicating that SJWE induced apoptosis through prodeath autophagy. Furthermore, SJWE inhibited tumor growth and induced autophagy and apoptosis in the tumor of MDA-MB-231 xenografted athymic nude mice. Our results indicate that SJWE might have great potential as a new anticancer therapy for triple-negative breast cancer by inducing prodeath autophagy and apoptosis.

Ras inhibition by zoledronic acid effectively sensitizes cervical cancer to chemotherapy

Aberrant activation of Ras is common in several human cancers, including cervical cancer. In this study, we show that Ras function can be inhibited by zoledronic acid (ZA) owing to its ability in inhibiting protein prenylation. Using in-vitro cell culture system and an in-vivo xenograft mouse model, the effects of ZA on cervical cancer cell growth and survival were determined. The molecular mechanisms of ZA's action were analyzed focusing on prenylation and its downstream signaling pathways. ZA inhibited proliferation and induced apoptosis of multiple cervical cancer cell lines regardless of their cellular origin and genetic profiling. The combination of ZA with paclitaxel or doxorubicin was superior to a single drug alone in cervical cancer in vitro and in vivo. Notably, complete inhibition of cervical cancer growth was observed in the combination groups. Mechanistically, ZA inhibited prenylation of oncoproteins. Ras activity was largely affected by ZA in a prenylation-dependent manner. Consistently, Ras-mediated signaling pathways such as Raf/ERK and AKt/mTOR were deactivated in cervical cancer cells exposed to ZA. Overexpression of constitutively active Ras reversed the inhibitory effects of ZA, confirming that Ras inhibition was required for the action of ZA in cervical cancer. Despite extensive efforts, there has been limited progress in the development of direct Ras inhibitors. Our findings suggest that ZA inhibits Ras activity. Our work provides fundamental evidence to repurpose ZA for the treatment of cervical cancer.

Effect of Curcumin and Its Derivates on Gastric Cancer: Molecular Mechanisms

Gastric carcinoma is one of the most prevalent malignancies and is associated with a high mortality. Chemotherapy is the principal therapeutic option in the treatment of gastric cancer, but its success rate is restricted by severe side effects and the prevalence of chemo-resistance. Curcumin is a polyphenolic compound derived from turmeric that has potent antioxidant, anti-inflammatory and anti-tumor effects. There is accumulating evidence that curcumin may prevent gastric cancer through regulation of oncogenic pathways. Furthermore some curcumin analogues and novel formulation of curcumin appear to have anti-tumor activity. The aim of this review was to give an overview of the therapeutic potential of curcumin and its derivatives against gastric cancer in preclinical and clinical studies.

12-Deacetyl-12-epi-Scalaradial, a Scalarane Sesterterpenoid from a Marine Sponge Hippospongia sp., Induces HeLa Cells Apoptosis via MAPK/ERK Pathway and Modulates Nuclear Receptor Nur77

12-Deacetyl-12-epi-scalaradial, a scalarane sesterterpenoid from a marine sponge Hippospongia sp, has been reported to possess cytotoxic activity on HepG2, MCF-7, and HCT-116 cells. However, there is no research to indicate that 12-deacetyl-12-epi-scalaradial exhibited anticancer effect on cervical cancer HeLa cells. The aim of this study was to investigate the anticancer activity of 12-deacetyl-12-epi-scalaradial against HeLa cells and to explore the mechanism. The results from a methylthiazolyldiphenyl-tetrazolium (MTT) assay suggested that 12-deacetyl-12-epi-scalaradial suppressed the proliferation of HeLa cells and flow cytometry analysis showed 12-deacetyl-12-epi-scalaradial could induce the apoptosis of HeLa cells in dose- and time-dependent manner. Western blotting analysis demonstrated that 12-deacetyl-12-epi-scalaradial triggered apoptosis via mediating the extrinsic pathway and was found to suppress MAPK/ERK pathway which was associate with cancer cell death. Nur77, a critical number of orphan nuclear receptors, plays diverse roles in tumor development as a transcription factor and has been considered as a promising anticancer drug target. The dual-luciferase reporter assays suggested that 12-deacetyl-12-epi-scalaradial could selectively enhance the trans-activation activity of Nur77. Furthermore, Western blotting analysis and fluorescence quenching showed that 12-deacetyl-12-epi-scalaradial could induce the phosphorylation of Nur77 and interact with the ligand-binding domain (LBD) of Nur77. Our research confirmed 12-deacetyl-12-epi-scalaradial as a potential agent for cervical cancer therapy and provided a view that 12-deacetyl-12-epi-scalaradial may be a modulator of Nur77.

The Expressions and Mechanisms of Sarcomeric Proteins in Cancers

The sarcomeric proteins control the movement of cells in diverse species, whereas the deregulation can induce tumours in model organisms and occurs in human carcinomas. Sarcomeric proteins are recognized as oncogene and related to tumor cell metastasis. Recent insights into their expressions and functions have led to new cancer therapeutic opportunities. In this review, we appraise the evidence for the sarcomeric proteins as cancer genes and discuss cancer-relevant biological functions, potential mechanisms by which sarcomeric proteins activity is altered in cancer.