Inhibition of PI3K/Akt/mTOR signaling pathway alleviates ovarian cancer chemoresistance through reversing epithelial-mesenchymal transition and decreasing cancer stem cell marker expression

Overcoming drug resistance in ovarian cancer through PI3K/AKT signaling inhibitors

Ovarian cancer has been identified as the eighth most typical gynaecological malignancy and cause of health problems in women. For almost forty years, platinum doublet chemotherapy has usually been the cornerstone of first-line treatment regimens. The effectiveness of conventional chemotherapy is severely hampered by relapse rates and mortality from chemotherapy resistance, which lead to the spread and recurrence of malignant cancers as well as poor outcomes in terms of quality of life in patients. Drug resistance has been linked to several mechanisms, including increased drug efflux, decreased apoptosis, increased autophagy, and changed drug metabolism. Further, the dysregulation of tumor suppressors or oncogenes plays a crucial role in chemoresistance. Additionally, PI3K/AKT/mTOR signaling has been implicated in several in vitro as well as clinical studies as a significant contributor to chemotherapy resistance in case of ovarian cancer. This review discusses the potential of various crude extracts, synthetic molecules, and nanoformulations for targeting PI3K/AKT/mTOR pathway. Moreover, a range of clinical studies involving PI3K/AKT/mTOR inhibitors have been summed up, addressing both the promises and complexities associated with their use. Overall, the review aims to provide a roadmap for future investigations that could lead to improved therapeutic outcomes for patients suffering from ovarian cancer, emphasizing the urgent need for continued exploration of novel pathways and strategies to combat drug resistance.

Carrier-Free Cisplatin-Dactolisib Nanoparticles for Enhanced Synergistic Antitumor Efficacy

Cisplatin (CDDP) is one of the most commonly used chemotherapeutic agents for solid tumors and hematologic malignancy. However, its therapeutic outcomes have remained unsatisfactory due to severe side effects, a short elimination half-life, the emergence of drug resistance, and the induction of metastasis. Combination with other chemotherapeutic agents has been proposed as one strategy to address the drawbacks of CDDP-based therapy. Therefore, this study aimed to boost the antitumor efficacy of cisplatin (CDDP) with a PI3K/mTOR dual inhibitor, dactolisib (BEZ), via a carrier-free codelivery system based on the self-assembly of the coordinated CDDP-BEZ. The synthesized CDDP-BEZ nanoparticles (NPs) possess sensitive pH-responsiveness, facilitating the delivery of both drugs to cancer cells. CDDP-BEZ NPs specifically enhanced cytotoxicity in cancer cells due to the synergy between cisplatin and dactolisib, resulting in augmented DNA damage, activation of mitochondria-dependent apoptosis, and increased inhibition on the PI3K/mTOR signaling axis. The inhibition of tumor migration and metastasis by CDDP-BEZ NPs was observed both in vitro and in vivo. Our data suggest that CDDP-BEZ NPs could serve as a safe and effective platform to maximize the synergy between both drugs in combating cancer, presenting a strategy to promote the therapeutic efficacy of platinum-based chemotherapeutic agents by combining them with PI3K inhibitors.

PI3Kα-specific inhibitor BYL-719 synergizes with cisplatin in vitro in PIK3CA-mutated ovarian cancer cells

Peritoneal carcinomatosis in ovarian cancer is often associated with ascites where cancer cells grow as aggregates. Given the emerging evidence that multicellular growth enhances resistance to conventional therapies, and that patients frequently develop resistance to platinum salts, we investigated the efficiency of PI3K/Akt signalling pathway targeting in multicellular growth and its importance as a potential therapeutic target in cells resistant to platinum salts. Due to its importance in many cancers and to the frequent mutations of its encoding gene PIK3CA, we focused on targeting PI3Kα using BYL-719 (Alpelisib), an isoform-specific inhibitor already used in clinics. We used a panel of 3 ovarian cancer cell lines, SKOV-3, EFO-21 and OVCAR-3, which come from different histological origins and bear different mutations. PI3K targeting drugs inhibit the activity of the PI3K/Akt pathway in all tested ovarian cancer cell lines with a drastic reduction of the phosphorylation of Akt on the serine 473, regardless the histology or the mutational profile. We showed that when cultured in 3D aggregates, ovarian cancer cells are more resistant to the PI3Kα-specific inhibitor BYL-719 and cisplatin compared to 2D monolayers. BYL-719 synergizes with cisplatin in 3D cultures only in PIK3CA-mutated SKOV-3 cells. This drug combination leads to a major cytotoxicity in 3D aggregates of this cell line. Finally, BYL-719 in combination with cisplatin remains active in 3D aggregates of SKOV-3 cells co-cultured with mesenchymal stem cells. We have identified a signalling pathway of interest for the treatment of advanced ovarian cancer in vitro, which could limit the progression of this disease. These data pave the road to investigate whether PI3Kα-specific inhibitor BYL-719 should be proposed in combination with cisplatin, in priority in patients bearing a PIK3CA mutation.

Phosphatidic acid as a cofactor of mTORC1 in platinum-based chemoresistance: Mechanisms and therapeutic potential

Platinum-based chemotherapeutics, such as cisplatin and carboplatin, are widely used to treat various malignancies. However, the development of chemoresistance remains a significant challenge, limiting their efficacy. This review explores the multifaceted mechanisms of platinum-based chemoresistance, with a particular focus on the mammalian target of rapamycin complex 1 (mTORC1) signaling pathway, which plays a critical role in promoting tumor survival and resistance to platinum compounds. Additionally, we examined the role of phosphatidic acid (PA) and its synthesizing enzymes, phospholipase D (PLD) and lysophosphatidic acid acyltransferase (LPAAT), in the regulation of mTORC1 activity. Given the involvement of mTORC1 in chemoresistance, we evaluated the potential of mTOR inhibitors as a therapeutic strategy to overcome platinum resistance. Finally, we discuss combination therapies targeting the mTOR pathway alongside conventional chemotherapy to improve treatment outcomes. This review highlights the potential of targeting mTORC1 and related pathways to improve therapeutic strategies for chemoresistant cancers.

Gold nanocomposites in colorectal cancer therapy: characterization, selective cytotoxicity, and migration inhibition

The third most prevalent type of cancer in the world, colorectal cancer, poses a significant treatment challenge due to the nonspecific distribution, low efficacy, and high systemic toxicity associated with chemotherapy. To overcome these limitations, a targeted drug delivery system with a high cytotoxicity against cancer cells while maintaining a minimal systemic side effects represents a promising therapeutic approach. Therefore, the aim of this study was to develop an efficient gold nanocarrier for the targeted delivery of the anticancer agent everolimus to Caco-2 cells. A novel gold nanocomposite (EV-β-CD-HA-Chi-AuNCs) functionalized with a targeting ligand (hyaluronic acid), a permeation enhancement excipient (chitosan), and an anticancer inclusive compound consisting of beta-cyclodextrin and everolimus was proposed and prepared via Turkevich method. Characterization was performed with a UV spectrometer, FTIR, Zetasizer, and HRTEM. Its drug release profile was also evaluated in media with three different pH values. Cytotoxicity and biocompatibility studies were performed on a colorectal cancer cell line (Caco-2) and a normal fibroblast line (MRC-5), respectively, via xCELLigence real-time cellular analysis (RTCA) technology. The inhibitory effect on migration was also further tested via the xCELLigence RTCA technique and a scratch assay. Characterization studies revealed the successful formation of EV-β-CD-HA-Chi-AuNCs with a size and charge which are suitable for the use as targeted drug delivery carrier. In the cytotoxic study, the EV-β-CD-HA-Chi-AuNCs showed a lower IC50 (16 ± 1 µg/ml) than the pure drug (25 ± 3 µg/ml) toward a colorectal cell line (Caco-2). In the biocompatibility study, the EV-β-CD-HA-Chi-AuNCs have minimal toxicity, while the pure drug has severe toxicity toward healthy fibroblasts (MRC-5) despite its low concentration. In the cell migration study, the EV-β-CD-HA-Chi-AuNCs also showed a greater inhibitory effect than the pure drug. Compared with the pure drug, the EV-β-CD-HA-Chi-AuNCs exhibit an excellent selective cytotoxicity between cancerous colorectal Caco-2 cells and healthy MRC-5 cells, making it a potential carrier to carry the drug to the cancerous site while maintaining its low toxicity to the surrounding environment. In addition, an increase in the cytotoxic activity of the EV-β-CD-HA-Chi-AuNCs toward cancerous colorectal Caco-2 cells was also observed, which can potentially improve the treatment of colorectal cancer.

Chloroquine Suppresses Colorectal Cancer Progression via Targeting CHKA and PFKM to inhibit the PI3K/AKT Pathway and the Warburg Effect

Colorectal cancer (CRC) is the second leading cause of cancer-related death worldwide and has become a recognized global health problem. Therefore, the search for new anti-CRC agents or the exploration of new effective drug targets for CRC therapy is urgent. Chloroquine (CQ) is a widely-used antimalarial drug and has shown anti-proliferative effects in CRC. However, the underlying mechanisms are not well understood, particularly as the direct targets of CQ have not been identified. In this study, choline kinase alpha (CHKA) and ATP-dependent 6-phosphofructokinase, muscle type (PFKM) were identified and verified as the binding targets of CQ. CQ specifically binds to CHKA, inhibits its expression and enzymatic activity, and downregulates the downstream phosphorylation of PI3K and AKT, thereby suppressing tumor cell proliferation and inducing apoptosis. CQ also binds to PFKM and inhibits its expression and activity, thereby blocking the Warburg effect. In addition, the downregulation of CHKA can decrease the expression of PFKM and inhibit its activity, thereby blocking the Warburg effect. These observations shed new light on the antitumor mechanisms of CQ and provide new evidence for the close relationship between the PI3K/AKT signaling pathway and the Warburg effect, providing new therapeutic targets for treating CRC.

Novel factors of cisplatin resistance in epithelial ovarian tumours

Ovarian tumours are these days one of the biggest oncogynecological problems. In addition to surgery, the treatment of ovarian cancer includes also chemotherapy in which platinum preparations are one of the most used chemotherapeutic drugs. The principle of antineoplastic effects of cisplatin (cis-diamminedichloroplatinum(II), CDDP) is its binding to the DNA and the formation of adducts. While DNA adducts induce the process of apoptosis, or inhibit the process of DNA replication, which prevents further division of tumour cells, various molecular mechanisms can reverse this process. On the other hand, with increasing scientific knowledge, it is becoming clearer that chemotherapy resistance is a very complex process. In this regard, factors and the amount of their expression may regulate the effect of resistance to chemotherapy. This review focuses on new molecular mechanisms and factors such as mitochondrial dynamics, epithelial-mesenchymal transition (EMT), cluster of differentiation, exosomes and others, that could be involved in the emergence of CDDP resistance.

Epithelial-mesenchymal transition in asthma: its role and underlying regulatory mechanisms

Bronchial asthma (asthma) is a respiratory disease characterized by chronic inflammation, airway hyperresponsiveness, and airway remodeling. Numerous studies have delved into asthma's pathogenesis, among which epithelial mesenchymal transition (EMT) is considered one of the important mechanisms in the pathogenesis of asthma. EMT refers to the transformation of epithelial cells, which lose their original features and acquire a migratory and invasive stromal phenotype. EMT contributes to normal physiological functions like growth, development, and wound healing. However, EMT is also involved in the occurrence and development of many diseases. Currently, the precise regulatory mechanism linking EMT and asthma remain obscure. Increasing evidence suggests that airway EMT contributes to asthma pathogenesis via dysregulation of associated control mechanisms. This review explores EMT's significance in asthma and the regulatory networks associated with EMT in this context.

Molecular mechanisms of mTOR-mediated cisplatin response in tumor cells

Cisplatin (CDDP) is one of the main chemotherapeutic drugs that is widely used in many cancers. However, CDDP resistance is a frequent therapeutic challenge that reduces prognosis in cancer patients. Since, CDDP has noticeable side effects in normal tissues and organs, it is necessary to assess the molecular mechanisms associated with CDDP resistance to improve the therapeutic methods in cancer patients. Drug efflux, detoxifying systems, DNA repair mechanisms, and drug-induced apoptosis are involved in multidrug resistance in CDDP-resistant tumor cells. Mammalian target of rapamycin (mTOR), as a serine/threonine kinase has a pivotal role in various cellular mechanisms such as autophagy, metabolism, drug efflux, and cell proliferation. Although, mTOR is mainly activated by PI3K/AKT pathway, it can also be regulated by many other signaling pathways. PI3K/Akt/mTOR axis functions as a key modulator of drug resistance and unfavorable prognosis in different cancers. Regarding, the pivotal role of mTOR in CDDP response, in the present review we discussed the molecular mechanisms that regulate mTOR mediated CDDP response in tumor cells.

NOS inhibition sensitizes metaplastic breast cancer to PI3K inhibition and taxane therapy via c-JUN repression

Metaplastic breast cancer (MpBC) is a highly chemoresistant subtype of breast cancer with no standardized therapy options. A clinical study in anthracycline-refractory MpBC patients suggested that nitric oxide synthase (NOS) inhibitor NG-monomethyl-l-arginine (L-NMMA) may augment anti-tumor efficacy of taxane. We report that NOS blockade potentiated response of human MpBC cell lines and tumors to phosphoinositide 3-kinase (PI3K) inhibitor alpelisib and taxane. Mechanistically, NOS blockade leads to a decrease in the S-nitrosylation of c-Jun NH2-terminal kinase (JNK)/c-Jun complex to repress its transcriptional output, leading to enhanced tumor differentiation and associated chemosensitivity. As a result, combined NOS and PI3K inhibition with taxane targets MpBC stem cells and improves survival in patient-derived xenograft models relative to single-/dual-agent therapy. Similarly, biopsies from MpBC tumors that responded to L-NMMA+taxane therapy showed a post-treatment reversal of epithelial-to-mesenchymal transition and decreased stemness. Our findings suggest that combined inhibition of iNOS and PI3K is a unique strategy to decrease chemoresistance and improve clinical outcomes in MpBC.

TRIM16 and PRC1 Are Involved in Pancreatic Cancer Progression and Targeted by Delphinidin

Pancreatic cancer (PC) is the leading cause of cancer-related death worldwide, and new biomarkers, therapeutic targets, and candidate drugs are needed. In this work, three PC-related microarray datasets (GSE183795, GSE28735, and GSE62452) were analyzed. The differentially expressed genes (DEGs) of PC were obtained with the limma package in R. Weighted gene co-expression network analysis (WGCNA) and machine learning approaches were used to screen the hub genes. Kaplan-Meier plotter and receiver operating characteristic (ROC) curve analysis were utilized to assess the diagnostic efficacy of the hub genes. The binding ability between natural bioactive ingredients and hub proteins was evaluated by molecular docking and molecular dynamics simulation. CCK-8, flow cytometry, transwell, and western blot assays were used to analyze the viability, apoptosis, cell cycle progression, invasion, and pathway change of PC cells. Additionally, a nude mice model was used to evaluate the aggressive properties of PC cells in vivo. In this study, a total of 988 DEGs were identified, which were mainly enriched in cell adhesion and PI3K-Akt signaling pathway, and two core genes TRIM16 and PRC1 were further identified. The overall survival of patients with high expression of TRIM16 and PRC1 was shorter. Delphinidin (Del) had good binding affinity with both TRIM16 and PRC1, and Del could inhibit the viability, invasion, and metastasis of PC cells and induce cell apoptosis and G0/G1 phase arrest. In addition, Del could promote the activation of p53 and inhibit the activation of the PI3K/AKT signaling pathway in PC cells. In summary, TRIM16 and PRC1 are identified as prognostic biomarkers and therapeutic targets for PC, and Del has good binding affinity with them and may be a potential therapeutic agent for PC.

Loss of XIST lncRNA unlocks stemness and cellular plasticity in ovarian cancer

Plasticity, a key hallmark of cancer, enables cells to transition into different states, driving tumor heterogeneity. This cellular plasticity is associated with cancer progression, treatment resistance, and relapse. Cancer stem cells (CSCs) play a central role in this process, yet the molecular factors underlying cancer cell stemness remain poorly understood. In this study, we explored the role of XIST (X-inactive specific transcript) long noncoding RNA in ovarian cancer stemness and plasticity through in silico and in vitro analyses. We found that XIST is significantly down-regulated in ovarian tumors, with low XIST expression linked to a higher stemness index and lower overall survival. Knocking down XIST in ovarian cancer cells enhanced stemness, particularly increasing mesenchymal-like CSCs, and under hypoxic conditions, it promoted epithelial-like CSC markers. Our findings suggest that XIST loss leads to CSC enrichment and cellular plasticity in ovarian cancer, pointing to potential therapeutic targets for patients with low XIST expression.

Roles of miRNAs in regulating ovarian cancer stemness

Ovarian cancer is one of the gynaecology malignancies with the highest mortality rate. Ovarian cancer stem cell (CSC) is a subpopulation of ovarian cancer cells with increased self-renewability, aggression, metastatic potentials, and resistance to conventional anti-cancer therapy. The emergence of ovarian CSC is a critical factor that promotes treatment resistance and frequent relapse among ovarian cancer patients, leading to poor clinical outcomes. MicroRNA (miRNA) is a short, non-protein-coding RNA that regulates ovarian CSC development. Although multiple original research articles have discussed the CSC-regulatory roles of different miRNAs in ovarian cancer, there is a deficiency of a review article that can summarize the findings from different research papers. To narrow the gap in the literature, this review aimed to provide an up-to-date summary of the CSC-regulatory roles of various miRNAs in modulating ovarian cancer cell stemness. This review will begin by giving an overview of ovarian CSC and the pathways responsible for driving its appearance. Next, the CSC-regulatory roles of miRNAs in controlling ovarian CSC development will be discussed. Overall, more than 60 miRNAs have been reported to play CSC-regulatory roles in the development and progression of ovarian cancer. By targeting various downstream targets, these miRNAs can control the signaling activities of PI3K/AKT, EGFR/ERK, WNT/ß-catenin, NF-kß, Notch, Hippo/YAP, EMT, and DNA repair pathways. Hence, these CSC-modulatory miRNAs have the potential to be used as prognostic biomarkers in predicting the clinical outcomes of ovarian cancer patients. Targeting CSC-promoting miRNAs or increasing the expressions of CSC-repressing miRNAs can help slow ovarian cancer progression. However, more in-depth functional and clinical trials must be carried out to evaluate the suitability, safety, sensitivity, and specificity of these CSC-regulating miRNAs as prognostic biomarkers or therapeutic targets.

A recent update on the connection between dietary phytochemicals and skin cancer: emerging understanding of the molecular mechanism

Constant exposure to harmful substances from both inside and outside the body can mess up the body's natural ways of keeping itself in balance. This can cause severe skin damage, including basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma. However, plant-derived compounds found in fruits and vegetables have been shown to protect against skin cancer-causing free radicals and other harmful substances. It has been determined that these dietary phytochemicals are effective in preventing skin cancer and are widely available, inexpensive, and well-tolerated. Studies have shown that these phytochemicals possess anti-inflammatory, antioxidant, and antiangiogenic properties that can aid in the prevention of skin cancers. In addition, they influence crucial cellular processes such as angiogenesis and cell cycle control, which can halt the progression of skin cancer. The present paper discusses the benefits of specific dietary phytochemicals found in fruits and vegetables, as well as the signaling pathways they regulate, the molecular mechanisms involved in the prevention of skin cancer, and their drawbacks.

Targeted therapy of cancer stem cells: inhibition of mTOR in pre-clinical and clinical research

Cancer stem cells (CSCs) are a type of stem cell that possesses not only the intrinsic abilities of stem cells but also the properties of cancer cells. Therefore, CSCs are known to have self-renewal and outstanding proliferation capacity, along with the potential to differentiate into specific types of tumor cells. Cancers typically originate from CSCs, making them a significant target for tumor treatment. Among the related cascades of the CSCs, mammalian target of rapamycin (mTOR) pathway is regarded as one of the most important signaling pathways because of its association with significant upstream signaling: phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) pathway and mitogen‑activated protein kinase (MAPK) cascade, which influence various activities of stem cells, including CSCs. Recent studies have shown that the mTOR pathway not only affects generation of CSCs but also the maintenance of their pluripotency. Furthermore, the maintenance of pluripotency or differentiation into specific types of cancer cells depends on the regulation of the mTOR signal in CSCs. Consequently, the clinical potential and importance of mTOR in effective cancer therapy are increasing. In this review, we demonstrate the association between the mTOR pathway and cancer, including CSCs. Additionally, we discuss a new concept for anti-cancer drug development aimed at overcoming existing drawbacks, such as drug resistance, by targeting CSCs through mTOR inhibition.

Nimodipine Used with Vincristine: Protects Schwann Cells and Neuronal Cells from Vincristine-Induced Cell Death but Increases Tumor Cell Susceptibility

The chemotherapeutic agent vincristine is commonly used for a variety of hematologic cancers, as well as solid tumors of the head and neck, bronchial carcinoma, as part of the procarbazine, lomustine and vincristine (PCV) regimen, for glioma. Damage to nerve tissue (neuropathy) is often dose-limiting and restricts treatment. Nimodipine is a calcium antagonist that has also shown neuroprotective properties in preliminary studies. In this approach here, we investigated the effects of the combination of vincristine and nimodipine on three cancer cell lines (A549, SAS and LN229) and neuronal cells (RN33B, SW10). Fluorescence microscopy, lactate dehydrogenase (LDH) assays and Western blot analyses were used. Nimodipine was able to enhance the cell death effects of vincristine in all tumor cells, while neuronal cells were protected and showed less cell death. There was an opposite change in the protein levels of Ak strain transforming/protein kinase B (AKT) in tumor cells (down) and neuronal cells (up), with simultaneous increased protein levels of cyclic adenosine monophosphate response element-binding protein (CREB) in all cell lines. In the future, this approach may improve tumor response to chemotherapy and reduce unwanted side effects such as neuropathy.

Current development of molecular classifications of gastric cancer based on omics (Review)

Gastric cancer (GC) is a complex and heterogeneous disease with significant phenotypic and genetic variation. Traditional classification systems rely mainly on the evaluation of clinical pathological features and conventional biomarkers and might not capture the diverse clinical processes of individual GCs. The latest discoveries in omics technologies such as next‑generation sequencing, proteomics and metabolomics have provided crucial insights into potential genetic alterations and biological events in GC. Clustering strategies for identifying subtypes of GC might offer new tools for improving GC treatment and clinical trial outcomes by enabling the development of therapies tailored to specific subtypes. However, the feasibility and therapeutic significance of implementing molecular classifications of GC in clinical practice need to addressed. The present review examines the current molecular classifications, delineates the prevailing landscape of clinically relevant molecular features, analyzes their correlations with traditional GC classifications, and discusses potential clinical applications.

Epithelial-mesenchymal plasticity in cancer: signaling pathways and therapeutic targets

Currently, cancer is still a leading cause of human death globally. Tumor deterioration comprises multiple events including metastasis, therapeutic resistance and immune evasion, all of which are tightly related to the phenotypic plasticity especially epithelial-mesenchymal plasticity (EMP). Tumor cells with EMP are manifest in three states as epithelial-mesenchymal transition (EMT), partial EMT, and mesenchymal-epithelial transition, which orchestrate the phenotypic switch and heterogeneity of tumor cells via transcriptional regulation and a series of signaling pathways, including transforming growth factor-β, Wnt/β-catenin, and Notch. However, due to the complicated nature of EMP, the diverse process of EMP is still not fully understood. In this review, we systematically conclude the biological background, regulating mechanisms of EMP as well as the role of EMP in therapy response. We also summarize a range of small molecule inhibitors, immune-related therapeutic approaches, and combination therapies that have been developed to target EMP for the outstanding role of EMP-driven tumor deterioration. Additionally, we explore the potential technique for EMP-based tumor mechanistic investigation and therapeutic research, which may burst vigorous prospects. Overall, we elucidate the multifaceted aspects of EMP in tumor progression and suggest a promising direction of cancer treatment based on targeting EMP.

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.

Recent Trends and Potential of Radiotherapy in the Treatment of Anaplastic Thyroid Cancer

Anaplastic thyroid cancer (ATC) is a rare but highly aggressive malignancy characterized by advanced disease at diagnosis and a poor prognosis. Despite multimodal therapeutic approaches that include surgery, radiotherapy, and chemotherapy, an optimal treatment strategy remains elusive. Current developments in targeted therapies and immunotherapy offer promising avenues for improved outcomes, particularly for BRAF-mutant patients. However, challenges remain regarding overcoming drug resistance and developing effective treatments for BRAF-wild-type tumors. This comprehensive review examines the clinical and biological features of ATC, outlines the current standards of care, and discusses recent developments with a focus on the evolving role of radiotherapy. Moreover, it emphasizes the necessity of a multidisciplinary approach and highlights the urgent need for further research to better understand ATC pathogenesis and identify new therapeutic targets. Collaborative efforts, including large-scale clinical trials, are essential for translating these findings into improved patient outcomes.

Signaling pathways in colorectal cancer implications for the target therapies

Colorectal carcinoma (CRC) stands as a pressing global health issue, marked by the unbridled proliferation of immature cells influenced by multifaceted internal and external factors. Numerous studies have explored the intricate mechanisms of tumorigenesis in CRC, with a primary emphasis on signaling pathways, particularly those associated with growth factors and chemokines. However, the sheer diversity of molecular targets introduces complexity into the selection of targeted therapies, posing a significant challenge in achieving treatment precision. The quest for an effective CRC treatment is further complicated by the absence of pathological insights into the mutations or alterations occurring in tumor cells. This study reveals the transfer of signaling from the cell membrane to the nucleus, unveiling recent advancements in this crucial cellular process. By shedding light on this novel dimension, the research enhances our understanding of the molecular intricacies underlying CRC, providing a potential avenue for breakthroughs in targeted therapeutic strategies. In addition, the study comprehensively outlines the potential immune responses incited by the aberrant activation of signaling pathways, with a specific focus on immune cells, cytokines, and their collective impact on the dynamic landscape of drug development. This research not only contributes significantly to advancing CRC treatment and molecular medicine but also lays the groundwork for future breakthroughs and clinical trials, fostering optimism for improved outcomes and refined approaches in combating colorectal carcinoma.

An Update on Physiopathological Roles of Akt in the ReprodAKTive Mammalian Ovary

The phosphoinositide 3-kinase (PI3K)/Akt pathway is a key signaling cascade responsible for the regulation of cell survival, proliferation, and metabolism in the ovarian microenvironment. The optimal finetuning of this pathway is essential for physiological processes concerning oogenesis, folliculogenesis, oocyte maturation, and embryo development. The dysregulation of PI3K/Akt can impair molecular and structural mechanisms that will lead to follicle atresia, or the inability of embryos to reach later stages of development. Due to its pivotal role in the control of cell proliferation, apoptosis, and survival mechanisms, the dysregulation of this molecular pathway can trigger the onset of pathological conditions. Among these, we will focus on diseases that can harm female fertility, such as polycystic ovary syndrome and premature ovarian failure, or women's general health, such as ovarian cancer. In this review, we report the functions of the PI3K/Akt pathway in both its physiological and pathological roles, and we address the existing application of inhibitors and activators for the balancing of the molecular cascade in ovarian pathological environments.

Targeting Oral Cancer: In Silico Docking Studies of Phytochemicals on Oncogenic Molecular Markers

OBJECTIVE

Molecular docking is a key tool in structural molecular biology and computer-assisted drug design. Oral carcinogenesis is a complex, multistep process in which genetic events within signal transduction pathways governing normal cellular physiology are quantitatively or qualitatively altered. There are various molecular targets like Cyclin D and PI3k- alpha Ras Binding Domain receptor protein involved in the pathogenesis of Oral Squamous Cell Carcinoma. The aim of the study is to demonstrate the computer aided drug design to identify a potent natural molecule for targeting cyclin D4 and PI3K RAS binding protein.

MATERIALS AND METHODS

Target selection (Cyclin D1 and PI3K-alpha Ras Binding Domain receptor) was done and structures were derived from protein data bank. Ligands (Apigenin, Chrysoeriol and Luteolin) selection was done and structure derived. Final docking was performed by Autodock.

RESULTS

From the docking results it can be seen that luteolin has the highest binding energy (-5.45) with the Cyclin D receptor molecule followed by Chrysoeriol (-4.99) and Apigenin (-4.96). The binding energies of the ligands against PI3K-alpha Ras Binding Domain receptors were Apigenin (-4.51), Chrysoeriol (-4.6) and Luteolin (-4.56).

CONCLUSION

The study concludes that all the three selected ligands possess high binding energy with both the target proteins involved in carcinogenesis with highest binding energy possessed by Luteolin against the Cyclin D receptor and by Chrysoeriol against PI3K-RAS binding protein. Thus their activity can be utilized to derive potential Anti-cancer therapeutic drugs.

An integrated investigation of sulfotransferases (SULTs) in hepatocellular carcinoma and identification of the role of SULT2A1 on stemness

The cytosolic sulfotransferases (SULTs) are phase II conjugating enzymes, which are widely expressed in the liver and mainly mediate the sulfation of numerous xenobiotics and endogenous compounds. However, the role of various SULTs genes has not been reported in hepatocellular carcinoma (HCC). This study aims to analyze the expression and potential functional roles of SULTs genes in HCC and to identify the role of SULT2A1 in HCC stemness as well as the possible mechanism. We found that all of the 12 SULTs genes were differentially expressed in HCC. Moreover, clinicopathological features and survival rates were also investigated. Multivariate regression analysis showed that SULT2A1 and SULT1C2 could be used as independent prognostic factors in HCC. SULT1C4, SULT1E1, and SULT2A1 were significantly associated with immune infiltration. SULT2A1 deficiency in HCC promoted chemotherapy resistance and stemness maintenance. Mechanistically, silencing of SULT2A1 activated the AKT signaling pathway, on the one hand, promoted the expression of downstream stemness gene c-Myc, on the other hand, facilitated the NRF2 expression to reduce the accumulation of ROS, and jointly increased HCC stemness. Moreover, knockdown NR1I3 was involved in the transcriptional regulation of SULT2A1 in stemness maintenance. In addition, SULT2A1 knockdown HCC cells promoted the proliferation and activation of hepatic stellate cells (HSCs), thereby exerting a potential stroma remodeling effect. Our study revealed the expression and role of SULTs genes in HCC and identified the contribution of SULT2A1 to the initiation and progression of HCC.

Protein homeostasis maintained by HOOK1 levels promotes the tumorigenic and stemness properties of ovarian cancer cells through reticulum stress and autophagy

BACKGROUND

Ovarian cancer has a high mortality rate mainly due to its resistance to currently used therapies. This resistance has been associated with the presence of cancer stem cells (CSCs), interactions with the microenvironment, and intratumoral heterogeneity. Therefore, the search for new therapeutic targets, particularly those targeting CSCs, is important for improving patient prognosis. HOOK1 has been found to be transcriptionally altered in a substantial percentage of ovarian tumors, but its role in tumor initiation and development is still not fully understood.

METHODS

The downregulation of HOOK1 was performed in ovarian cancer cell lines using CRISPR/Cas9 technology, followed by growth in vitro and in vivo assays. Subsequently, migration (Boyden chamber), cell death (Western-Blot and flow cytometry) and stemness properties (clonal heterogeneity analysis, tumorspheres assay and flow cytometry) of the downregulated cell lines were analysed. To gain insights into the specific mechanisms of action of HOOK1 in ovarian cancer, a proteomic analysis was performed, followed by Western-blot and cytotoxicity assays to confirm the results found within the mass spectrometry. Immunofluorescence staining, Western-blotting and flow cytometry were also employed to finish uncovering the role of HOOK1 in ovarian cancer.

RESULTS

In this study, we observed that reducing the levels of HOOK1 in ovarian cancer cells reduced in vitro growth and migration and prevented tumor formation in vivo. Furthermore, HOOK1 reduction led to a decrease in stem-like capabilities in these cells, which, however, did not seem related to the expression of genes traditionally associated with this phenotype. A proteome study, along with other analysis, showed that the downregulation of HOOK1 also induced an increase in endoplasmic reticulum stress levels in these cells. Finally, the decrease in stem-like properties observed in cells with downregulated HOOK1 could be explained by an increase in cell death in the CSC population within the culture due to endoplasmic reticulum stress by the unfolded protein response.

CONCLUSION

HOOK1 contributes to maintaining the tumorigenic and stemness properties of ovarian cancer cells by preserving protein homeostasis and could be considered an alternative therapeutic target, especially in combination with inducers of endoplasmic reticulum or proteotoxic stress such as proteasome inhibitors.

Uncovering miRNA-mRNA Regulatory Networks Related to Olaparib Resistance and Resensitization of BRCA2MUT Ovarian Cancer PEO1-OR Cells with the ATR/CHK1 Pathway Inhibitors

Resistance to olaparib is the major obstacle in targeted therapy for ovarian cancer (OC) with poly(ADP-ribose) polymerase inhibitors (PARPis), prompting studies on novel combination therapies to enhance olaparib efficacy. Despite identifying various mechanisms, understanding how OC cells acquire PARPi resistance remains incomplete. This study investigated microRNA (miRNA) expression in olaparib-sensitive (PEO1, PEO4) and previously established olaparib-resistant OC cell lines (PEO1-OR) using high-throughput RT-qPCR and bioinformatic analyses. The role of miRNAs was explored regarding acquired resistance and resensitization with the ATR/CHK1 pathway inhibitors. Differentially expressed miRNAs were used to construct miRNA-mRNA regulatory networks and perform functional enrichment analyses for target genes with miRNet 2.0. TCGA-OV dataset was analyzed to explore the prognostic value of selected miRNAs and target genes in clinical samples. We identified potential processes associated with olaparib resistance, including cell proliferation, migration, cell cycle, and growth factor signaling. Resensitized PEO1-OR cells were enriched in growth factor signaling via PDGF, EGFR, FGFR1, VEGFR2, and TGFβR, regulation of the cell cycle via the G2/M checkpoint, and caspase-mediated apoptosis. Antibody microarray analysis confirmed dysregulated growth factor expression. The addition of the ATR/CHK1 pathway inhibitors to olaparib downregulated FGF4, FGF6, NT-4, PLGF, and TGFβ1 exclusively in PEO1-OR cells. Survival and differential expression analyses for serous OC patients revealed prognostic miRNAs likely associated with olaparib resistance (miR-99b-5p, miR-424-3p, and miR-505-5p) and resensitization to olaparib (miR-324-5p and miR-424-3p). Essential miRNA-mRNA interactions were reconstructed based on prognostic miRNAs and target genes. In conclusion, our data highlight distinct miRNA profiles in olaparib-sensitive and olaparib-resistant cells, offering molecular insights into overcoming resistance with the ATR/CHK1 inhibitors in OC. Moreover, some miRNAs might serve as potential predictive signature molecules of resistance and therapeutic response.

Signaling, cancer cell plasticity, and intratumor heterogeneity

Cancer's complexity is in part due to the presence of intratumor heterogeneity and the dynamic nature of cancer cell plasticity, which create substantial obstacles in effective cancer management. Variability within a tumor arises from the existence of diverse populations of cancer cells, impacting the progression, spread, and resistance to treatments. At the core of this variability is the concept of cellular plasticity - the intrinsic ability of cancer cells to alter their molecular and cellular identity in reaction to environmental and genetic changes. This adaptability is a cornerstone of cancer's persistence and progression, making it a formidable target for treatments. Emerging studies have emphasized the critical role of such plasticity in fostering tumor diversity, which in turn influences the course of the disease and the effectiveness of therapeutic strategies. The transformative nature of cancer involves a network of signal transduction pathways, notably those that drive the epithelial-to-mesenchymal transition and metabolic remodeling, shaping the evolutionary path of cancer cells. Despite advancements, our understanding of the precise molecular machinations and signaling networks driving these changes is still evolving, underscoring the necessity for further research. This editorial presents a series entitled "Signaling Cancer Cell Plasticity and Intratumor Heterogeneity" in Cell Communication and Signaling, dedicated to unraveling these complex processes and proposing new avenues for therapeutic intervention.

Zinc Oxide Nanoparticles and Cancer Chemotherapy: Helpful Tools for Enhancing Chemo-sensitivity and Reducing Side Effects?

Cancer chemotherapy is still a serious challenge. Chemo-resistance and destructive side effects of chemotherapy drugs are the most critical limitations of chemotherapy. Chemo-resistance is the leading cause of chemotherapy failure. Chemo-resistance, which refers to the resistance of cancer cells to the anticancer effects of chemotherapy drugs, is caused by various reasons. Among the most important of these reasons is the increase in the efflux of chemotherapy drugs due to the rise in the expression and activity of ABC transporters, the weakening of apoptosis, and the strengthening of stemness. In the last decade, a significant number of studies focused on the application of nanotechnology in cancer treatment. Considering the anti-cancer properties of zinc, zinc oxide nanoparticles have received much attention in recent years. Some studies have indicated that zinc oxide nanoparticles can target the critical mechanisms of cancer chemo-resistance and enhance the effectiveness of chemotherapy drugs. These studies have shown that zinc oxide nanoparticles can reduce the activity of ABC transporters, increase DNA damage and apoptosis, and attenuate stemness in cancer cells, leading to enhanced chemo-sensitivity. Some other studies have also shown that zinc oxide nanoparticles in low doses can be helpful in minimizing the harmful side effects of chemotherapy drugs. In this article, after a brief overview of the mechanisms of chemo-resistance and anticancer effects of zinc, we will review all these studies in detail.

Spotlight on New Hallmarks of Drug-Resistance towards Personalized Care for Epithelial Ovarian Cancer

Epithelial ovarian cancer (EOC) is the deadliest gynecological malignancy worldwide. Despite the latest advances, a major clinical issue in EOC is the disappointing prognosis related to chemoresistance in almost one-third of cases. Drug resistance relies on heterogeneous cancer stem cells (CSCs), endowed with tumor-initiating potential, leading to relapse. No biomarkers of chemoresistance have been validated yet. Recently, major signaling pathways, micro ribonucleic acids (miRNAs), and circulating tumor cells (CTCs) have been advocated as putative biomarkers and potential therapeutic targets for drug resistance. However, further investigation is mandatory before their routine implementation. In accordance with the increasing rate of therapeutic efforts in EOC, the need for biomarker-driven personalized therapies is growing. This review aims to discuss the emerging hallmarks of drug resistance with an in-depth insight into the underlying molecular mechanisms lacking so far. Finally, a glimpse of novel therapeutic avenues and future challenges will be provided.

Evaluating synergistic effects of metformin and simvastatin on ovarian cancer cells

BACKGROUND

Ovarian Cancer (OC) stands as the most lethal gynecological malignancy, presenting an urgent clinical challenge in the quest to improve response rates. One approach to address this challenge is through drug repurposing, exemplified by the investigation of metabolic-modulating drugs such as Metformin (MTF) and Simvastatin (SIM). This study aims to explore the molecular mechanisms contributing to the potential synergistic anti-cancer effects between MTF and SIM on ovarian cancer cells.

METHODS

We assessed the effects of the combination on the proliferation and viability of two cell lines OVCAR-3 and SKOV-3. IC50 concentrations of MTF and SIM were determined using a proliferation assay, followed by subtoxic concentrations to explore the potential synergistic effects on the viability of both cell lines. Transcriptomic analysis was conducted on OVCAR-3 treated cells, and the findings were validated by assessing the expression levels of differentially expressed genes (DEGs) through real-time PCR in both cell lines SK-OV-3 and OVCAR-3.

RESULTS

Cytotoxicity analysis guided the selection of treatment concentrations as such MTF 10 mM and SIM 5 μM. The combined treatment of MTF and SIM demonstrated a synergistic inhibition of proliferation and viability in both cell lines. In OVCAR-3, exclusive identification of 507 DEGs was seen in the combination arm. Upregulation of FOXO3, RhoA, and TNFα, along with downregulation of PIK3R1, SKP2, and ATP6V1D levels, was observed in OVCAR-3 treated cells. Real-time PCR validation confirmed the consistency of expression levels for the mentioned DEGs.

CONCLUSION

Our data strongly supports the presence of synergy between MTF and SIM in OC cells. The combination's effect is associated with the dysregulation of genes in the key regulators AMPK and mTOR alongside other interconnected pathways.

Establishment and characterization of cisplatin-resistant cell lines from canine mammary gland tumors

The development of cisplatin resistance is one of the major causes of mammary cancer treatment failure, and is associated with changes in Sox4 gene expression. To investigate the characteristic changes that occur in canine mammary gland tumor (CMGT) cells following the development of acquired cisplatin resistance, along with the relationship between these changes and the Sox4 gene. We constructed cisplatin-resistant cell line, CHMpCIS, from the cell line CHMp, which was isolated from the primary lesion of a malignant CMGT. The biological characteristics of these cells were examined by Western blot analysis, Transwell assays, and mammosphere formation assays. Compared to CHMp cells, CHMpCIS cells exhibited elevated cisplatin resistance, apoptotic escape ability, enhanced epithelial-mesenchymal transition (EMT) and cancer stem cell (CSC) features, in addition to over-activation of the Wnt/β-catenin signaling pathway and increased Sox4 protein. In CMGT cases, CMGT tissues (CMGTT) expressed higher levels of Sox4 protein and mRNA compared to adjacent tissues (CAMGTT). We found that these changes were inhibited by silencing of Sox4 expression in CHMpCIS cells. Furthermore, activation of the Wnt/β-catenin signaling pathway increased Sox4 expression levels through a positive feedback loop. These results suggested that CHMpCIS cells circumvented the damage caused by cisplatin through altering the expression of the Sox4 gene and activating the Wnt/β-catenin pathway, thereby changing the cellular biological characteristics.

Targeting the PI3K/AKT signaling pathway in anticancer research: a recent update on inhibitor design and clinical trials (2020-2023)

INTRODUCTION

Recent years have witnessed great achievements in drug design and development targeting the phosphatidylinositol 3-kinase/protein kinase-B (PI3K/AKT) signaling pathway, a pathway central to cell growth and proliferation. The nearest neighbor protein-protein interaction networks for PI3K and AKT show the interplays between these target proteins which can be harnessed for drug discovery. In this review, we discuss the drug design and clinical development of inhibitors of PI3K/AKT in the past three years. We review in detail the structures, selectivity, efficacy, and combination therapy of 35 inhibitors targeting these proteins, classified based on the target proteins. Approaches to overcoming drug resistance and to minimizing toxicities are discussed. Future research directions for developing combinational therapy and PROTACs of PI3K and AKT inhibitors are also discussed.

AREA COVERED

This review covers clinical trial reports and patent literature on inhibitors of PI3K and AKT published between 2020 and 2023.

EXPERT OPINION

To address drug resistance and drug toxicity of inhibitors of PI3K and AKT, it is highly desirable to design and develop subtype-selective PI3K inhibitors or subtype-selective AKT1 inhibitors to minimize toxicity or to develop allosteric drugs that can form covalent bonds. The development of PROTACs of PI3Kα or AKT helps to reduce off-target toxicities.

Curcumin suppresses metastasis of triple-negative breast cancer cells by modulating EMT signaling pathways: An integrated study of bioinformatics analysis

This study aimed to use bioinformatics approaches for predicting the anticancer mechanisms of curcumin on triple-negative breast cancer (TNBC) and to verify these predictions through in vitro experiments. Initially, the Cell Counting Kit-8 (CCK8) assay was employed to rigorously investigate the influence of curcumin on the proliferative capacity of TNBC cells. Subsequently, flow cytometry was employed to meticulously assess the impact of curcumin on cellular apoptosis and the cell cycle regulation. Transwell assays were employed to meticulously evaluate the effect of curcumin on the motility of TNBC cells. RNA sequencing was conducted, followed by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses of differentially expressed genes, aiming to elucidate the potential anticancer mechanisms underlying curcumin's effects. To thoroughly elucidate the interactions among multiple proteins, we constructed a protein-protein interaction (PPI) network. Finally, the expression levels of several key proteins, including fibronectin, mTOR, β-Catenin, p-Akt, Akt, N-Cadherin, p-S6, and S6, were assessed using the western blot. The CCK8 assay results showed that curcumin significantly inhibited the proliferation of Hs578T and MDA-MB-231 cells. Flow cytometry results showed that curcumin induced apoptosis in these cells and arrested the cell cycle at the G2/M phase. Additionally, Transwell assay results showed that curcumin effectively reduced the motility of Hs578T and MDA-MB-231 cells. Enrichment analysis of RNA sequencing data showed that the mechanism of action of curcumin was significantly associated with signaling pathways such as pathways in cancer, focal adhesion, and PI3K-Akt signaling pathways. Subsequently, we constructed a protein-protein interaction network to elucidate the interactions among multiple proteins. Finally, Western blotting analysis showed that curcumin significantly decreased the expression levels of key proteins including Fibronectin, mTOR, β-Catenin, p-Akt, Akt, N-Cadherin, p-S6, and S6. Curcumin exhibits its therapeutic potential in TNBC by modulating multiple signaling pathways. It may inhibit the epithelial-mesenchymal transition process by downregulating the expression of proteins involved in the mTOR and PI3K-Akt signaling pathways, thereby suppressing the motility of TNBC cells. These findings provide experimental evidence for considering curcumin as a potential therapeutic strategy in the treatment of TNBC.

A Recipe for Successful Metastasis: Transition and Migratory Modes of Ovarian Cancer Cells

One of the characteristic features of ovarian cancer is its early dissemination. Metastasis and the invasiveness of ovarian cancer are strongly dependent on the phenotypical and molecular determinants of cancer cells. Invasive cancer cells, circulating tumor cells, and cancer stem cells, which are responsible for the metastatic process, may all undergo different modes of transition, giving rise to mesenchymal, amoeboid, and redifferentiated epithelial cells. Such variability is the result of the changing needs of cancer cells, which strive to survive and colonize new organs. This would not be possible if not for the variety of migration modes adopted by the transformed cells. The most common type of metastasis in ovarian cancer is dissemination through the transcoelomic route, but transitions in ovarian cancer cells contribute greatly to hematogenous and lymphatic dissemination. This review aims to outline the transition modes of ovarian cancer cells and discuss the migratory capabilities of those cells in light of the known ovarian cancer metastasis routes.

Ursolic acid inhibits the metastasis of colon cancer by downregulating ARL4C expression

Ursolic acid (UA), a natural pentacyclic triterpenoid, is known to exhibit various biological activities and anticancer effects. However, the underlying anticancer mechanism is not fully understood to date. The present study aimed to investigate the antimetastatic effect of UA through ADP‑ribosylation factor like GTPase 4C (ARL4C) in colon cancer. A lung metastasis model of colon cancer in nude mice was established through tail vein injection. A Cell Counting Kit‑8 assay was used to investigate the proliferation of colon cancer cells. Transwell assays were used to detect cell migration and invasion. The expression levels of proteins including ARL4C, matrix metallopeptidase 2 (MMP2), phosphorylated (p)‑AKT and p‑mTOR were measured using western blot analysis. Immunohistochemistry was used to determine the protein expression level in tissues. ARL4C ubiquitination levels were analysed using immunoprecipitation and western blotting. The results indicated that UA inhibits the metastasis of colon cancer in vivo and in vitro. The expression of ARL4C in human colon cancer tissue was significantly higher than that in adjacent tissues and its high expression level was associated with lymph node metastases and tumour stage. UA treatment significantly decreased ARL4C and MMP2 protein levels and inhibited the AKT/mTOR signalling pathway. Overexpression of ARL4C reversed the inhibitory effect of UA on the invasion and migration of HCT‑116 and SW480 cells, as well as the expression and secretion of MMP2 protein. In addition, UA and an AKT signalling pathway inhibitor (LY294002) induced the ubiquitination of the ARL4C protein, which was reversed by a proteasome inhibitor (MG‑132). Collectively, it was revealed in the present study that UA served as a novel solution to relieve colon cancer metastasis by inducing the ubiquitination‑mediated degradation of ARL4C by modulating the AKT signalling pathway. Thus, UA may be a promising treatment option to prolong the survival of patients with colon cancer metastasis.

Cancer Stem Cells and Treatment of Cancer: An Update and Future Perspectives

Cancer stem cells (CSCs) play an essential role in tumour progression and metastasis. Stem cell ability of self-renewal enables it to persist over time, thereby contributing to cancer relapse or recurrence and also resistance to current therapies. Therefore, targeting CSCs emerged as a promising strategy of cancer treatment. CSCs exhibit differentiation, self-renewal, and plasticity, they contribute to formation of malignant tumours, also favors, metastasis, heterogeneity, multidrug resistance, and radiation resistance. Coventional cancer treatments predominantly target cancer cells that are not CSCs, CSCs frequently survive, eventually leading to relapse. This article focuses on the development of novel therapeutic strategies that combine conventional treatments and CSC inhibitors to eradicate cancer cells and CSCs, for the better and permanent treatment. However, the diversity of CSCs is a significant obstacle in the development of CSC-targeted therapies, necessitating extensive research for a better understanding and exploration of therapeutic approaches. Future development of CSC-targeted therapies will rely heavily on overcoming this obstacle.

Exploring the Mechanism of Brucea Javanica against Ovarian Cancer based on Network Pharmacology and the Influence of Luteolin on the PI3K/AKT Pathway

BACKGROUND

Ovarian cancer (OC) is a commonly diagnosed female cancer around the world. The Chinese herbal medicine Brucea Javanica has an anti-cancer effect. However, there is no relevant report on whether Brucea Javanica is effective in treating OC, and the corresponding mechanism is also unknown.

OBJECTIVE

This study was projected to excavate the active components and underpinned molecular mechanisms of Brucea Javanica in treating ovarian cancer (OC) through network pharmacology combined with in vitro experiments.

METHODS

The essential active components of Brucea Javanica were selected using the TCMSP database. The OC-related targets were selected by GeneCards, intersecting targets were obtained by Venn Diagram. The core targets were obtained through the PPI network and Cytoscape, and the key pathway was gained through GO and KEGG enrichment analyses. Meanwhile, docking conformation was observed as reflected by molecular docking. MTT, colony formation assay and flow cytometer (FCM) analysis were performed to determine cell proliferation and apoptosis, respectively. Finally, Levels of various signaling proteins were evaluated by western blotting.

RESULTS

Luteolin, β-sitosterol and their corresponding targets were selected as the essential active components of Brucea Javanica. 76 intersecting targets were obtained by Venn Diagram. TP53, AKT1, and TNF were obtained through the PPI network and Cytoscape, and the key pathway PI3K/AKT was gained through GO and KEGG enrichment analyses. A good docking conformation was observed between luteolin and AKT1. Luteolin could hinder A2780 cell proliferation, induce cell apoptosis and enhance the inhibition of the PI3K/AKT pathway.

CONCLUSION

It was verified in vitro that luteolin could hinder OC cell proliferation and activate the PI3K/AKT pathway to lead to apoptosis.

EXOSC5 maintains cancer stem cell activity in endometrial cancer by regulating the NTN4/integrin β1 signalling axis

Endometrial carcinoma (EC) is a common type of uterine cancer in developed countries, originating from the uterine epithelium. The incidence rate of EC in Taiwan has doubled from 2005. Cancer stem cells (CSCs) are a subpopulation of cancer cells that have high tumorigenicity and play a crucial role in the malignant processes of cancer. Targeting molecules associated with CSCs is essential for effective cancer treatments. This study delves into the role of Exosome component 5 (EXOSC5) in EC. Data from The Cancer Genome Atlas suggests a correlation between high EXOSC5 mRNA expression and unfavorable EC prognosis. EXOSC5 knockdown diminished EC-CSC self-renewal and reduced expression of key cancer stemness proteins, including c-MYC and SOX2. Intriguingly, this knockdown significantly curtailed tumorigenicity and CSC frequency in EC tumor spheres. A mechanistic examination revealed a reduction in netrin4 (NTN4) levels in EXOSC5-depleted EC cells. Moreover, NTN4 treatment amplified EC cell CSC activity and, when secreted, NTN4 partnered with integrin β1, subsequently triggering the FAK/SRC axis to elevate c-MYC activity. A clear positive relation between EXOSC5 and NTN4 was evident in 93 EC tissues. In conclusion, EXOSC5 augments NTN4 expression, activating c-MYC via the integrin β1/FAK/SRC pathway, offering potential avenues for EC diagnosis and treatment.

Targeting KRAS-Mutated Gastrointestinal Malignancies with Small-Molecule Inhibitors: A New Generation of Breakthrough Therapies

Kirsten rat sarcoma virus (KRAS) is one of the most important and frequently mutated oncogenes in cancer and the mutational prevalence is especially high in many gastrointestinal malignancies, including colorectal cancer and pancreatic ductal adenocarcinoma. The KRAS protein is a small GTPase that functions as an "on/off" switch to activate downstream signaling, mainly through the mitogen-activated protein kinase pathway. KRAS was previously considered undruggable because of biochemical constraints; however, recent breakthroughs have enabled the development of small-molecule inhibitors of KRAS G12C. These drugs were initially approved in lung cancer and have now shown substantial clinical activity in KRAS G12C-mutated pancreatic ductal adenocarcinoma as well as colorectal cancer when combined with anti-EGFR monoclonal antibodies. Early data are encouraging for other gastrointestinal cancers as well and many other combination strategies are being investigated. Several new KRAS G12C inhibitors and novel inhibitors of other KRAS alterations have recently entered the clinic. These molecules employ a variety of innovative mechanisms and have generated intense interest. These novel drugs are especially important as KRAS G12C is rare in gastrointestinal malignancies compared with other KRAS alterations, representing potentially groundbreaking advances. Soon, the rapidly evolving landscape of novel KRAS inhibitors may substantially shift the therapeutic landscape for gastrointestinal cancers and offer meaningful survival improvements.

The Role of Cancer Stem Cell Markers in Ovarian Cancer

Ovarian cancer is the most lethal gynaecological cancer and the eighth most common female cancer. The early diagnosis of ovarian cancer remains a clinical problem despite the significant development of technology. Nearly 70% of patients with ovarian cancer are diagnosed with stages III-IV metastatic disease. Reliable diagnostic and prognostic biomarkers are currently lacking. Ovarian cancer recurrence and resistance to chemotherapy pose vital problems and translate into poor outcomes. Cancer stem cells appear to be responsible for tumour recurrence resulting from chemotherapeutic resistance. These cells are also crucial for tumour initiation due to the ability to self-renew, differentiate, avoid immune destruction, and promote inflammation and angiogenesis. Studies have confirmed an association between CSC occurrence and resistance to chemotherapy, subsequent metastases, and cancer relapses. Therefore, the elimination of CSCs appears important for overcoming drug resistance and improving prognoses. This review focuses on the expression of selected ovarian CSC markers, including CD133, CD44, CD24, CD117, and aldehyde dehydrogenase 1, which show potential prognostic significance. Some markers expressed on the surface of CSCs correlate with clinical features and can be used for the diagnosis and prognosis of ovarian cancer. However, due to the heterogeneity and plasticity of CSCs, the determination of specific CSC phenotypes is difficult.

Sniping Cancer Stem Cells with Nanomaterials

Cancer stem cells (CSCs) drive tumor initiation, progression, and therapeutic resistance due to their self-renewal and differentiation capabilities. Despite encouraging progress in cancer treatment, conventional approaches often fail to eliminate CSCs, necessitating the development of precise targeted strategies. Recent advances in materials science and nanotechnology have enabled promising CSC-targeted approaches, harnessing the power of tailoring nanomaterials in diverse therapeutic applications. This review provides an update on the current landscape of nanobased precision targeting approaches against CSCs. We elucidate the nuanced application of organic, inorganic, and bioinspired nanomaterials across a spectrum of therapeutic paradigms, encompassing targeted therapy, immunotherapy, and multimodal synergistic therapies. By examining the accomplishments and challenges in this potential field, we aim to inform future efforts to advance nanomaterial-based therapies toward more effective "sniping" of CSCs and tumor clearance.

Defining the Role of Metastasis-Initiating Cells in Promoting Carcinogenesis in Ovarian Cancer

Ovarian cancer is the deadliest gynecological malignancy with a high prevalence of transcoelomic metastasis. Metastasis is a multi-step process and only a small percentage of cancer cells, metastasis-initiating cells (MICs), have the capacity to finally establish metastatic lesions. These MICs maintain a certain level of stemness that allows them to differentiate into other cell types with distinct transcriptomic profiles and swiftly adapt to external stresses. Furthermore, they can coordinate with the microenvironment, through reciprocal interactions, to invade and establish metastases. Therefore, identifying, characterizing, and targeting MICs is a promising strategy to counter the spread of ovarian cancer. In this review, we provided an overview of OC MICs in the context of characterization, identification through cell surface markers, and their interactions with the metastatic niche to promote metastatic colonization.

Long noncoding RNA FTX promotes epithelial-mesenchymal transition of epithelial ovarian cancer through modulating miR-7515/TPD52 and activating Met/Akt/mTOR

Overexpressed long noncoding RNA FTX is associated with low survival rate of epithelial ovarian cancer (EOC) patients, and enhances tumor infiltration. Thus, we aim to illuminate the undefined underlying mechanisms. Real-time quantitative polymerase chain reaction was applied to detect the expressions of FTX, miR-7515, miR-342-3p, miR-940, miR-150-5p, miR-205-5p and tumor protein D52 (TPD52). Cell counting kit-8 and transwell assays were utilized to explore the cell viability, migration or invasion of EOC cells. Western blot was conducted to measure the expressions of E-cadherin, N-cadherin, Met, phosphorylated (p)-Met, Akt, p-Akt, mTOR and p-mTOR. LncBase and TargetScan predicted the binding of miR-7515 with FTX, and the binding of TPD52 with miR-7515, respectively. The two bindings were further validated by dual luciferase reporter assay. As a result, FTX sponged miR-7515 and miR-7515 targeted to TPD52. FTX was overexpressed in four EOC cell lines. Overexpressed FTX enhanced the cell viability, migration or invasion of EOC cells, elevated N-cadherin and TPD52 expressions, phosphorylated Met/Akt/mTOR, and inhibited E-cadherin expression. All these influences were subsequently reversed by miR-7515 mimic. Collectively, FTX regulates miR-7515/TPD52 to facilitate the migration, invasion or epithelial-mesenchymal transition of EOC through activating Met/Akt/mTOR signaling pathway.

Molecular mechanisms of resveratrol as chemo and radiosensitizer in cancer

One of the primary diseases that cause death worldwide is cancer. Cancer cells can be intrinsically resistant or acquire resistance to therapies and drugs used for cancer treatment through multiple mechanisms of action that favor cell survival and proliferation, becoming one of the leading causes of treatment failure against cancer. A promising strategy to overcome chemoresistance and radioresistance is the co-administration of anticancer agents and natural compounds with anticancer properties, such as the polyphenolic compound resveratrol (RSV). RSV has been reported to be able to sensitize cancer cells to chemotherapeutic agents and radiotherapy, promoting cancer cell death. This review describes the reported molecular mechanisms by which RSV sensitizes tumor cells to radiotherapy and chemotherapy treatment.

Drug resistance and immunotherapy in gynecologic cancers

Gynecologic malignancies (GMs) are relatively less focused cancers by oncologists and researchers. The five-year survival rate of patients with GMs remained almost the same during the last decade. The development of drug resistance GMs makes it even more challenging to tackle due to tumor heterogeneity, genomic instability, viral/non-viral antigens, and etiological tumor origin. A precision medicine approach, including gene therapies, is under testing to restore tumor responsiveness to therapeutics and immunotherapy. With more data being uncovered, immunotherapy is emerging as a viable alternative for achieving promising results. This review highlights the drug resistance mechanisms and immunotherapeutic approaches to managing GMs better. The approval of immune therapeutic drugs in recent years shifted this notion. It provided hope for researchers, clinicians, and patients with GMs to experience the anti-cancer benefits of these therapies.

Down-Regulation of CYP3A4 by the KCa1.1 Inhibition Is Responsible for Overcoming Resistance to Doxorubicin in Cancer Spheroid Models

The large-conductance Ca2+-activated K+ channel, KCa1.1, plays a pivotal role in cancer progression, metastasis, and the acquisition of chemoresistance. Previous studies indicated that the pharmacological inhibition of KCa1.1 overcame resistance to doxorubicin (DOX) by down-regulating multidrug resistance-associated proteins in the three-dimensional spheroid models of human prostate cancer LNCaP, osteosarcoma MG-63, and chondrosarcoma SW-1353 cells. Investigations have recently focused on the critical roles of intratumoral, drug-metabolizing cytochrome P450 enzymes (CYPs) in chemoresistance. In the present study, we examined the involvement of CYPs in the acquisition of DOX resistance and its overcoming by inhibiting KCa1.1 in cancer spheroid models. Among the CYP isoforms involved in DOX metabolism, CYP3A4 was up-regulated by spheroid formation and significantly suppressed by the inhibition of KCa1.1 through the transcriptional repression of CCAAT/enhancer-binding protein, CEBPB, which is a downstream transcription factor of the Nrf2 signaling pathway. DOX resistance was overcome by the siRNA-mediated inhibition of CYP3A4 and treatment with the potent CYP3A4 inhibitor, ketoconazole, in cancer spheroid models. The phosphorylation levels of Akt were significantly reduced by inhibiting KCa1.1 in cancer spheroid models, and KCa1.1-induced down-regulation of CYP3A4 was reversed by the treatment with Akt and Nrf2 activators. Collectively, the present results indicate that the up-regulation of CYP3A4 is responsible for the acquisition of DOX resistance in cancer spheroid models, and the inhibition of KCa1.1 overcame DOX resistance by repressing CYP3A4 transcription mainly through the Akt-Nrf2-CEBPB axis.

Combined PI3K Inhibitor and Eribulin Enhances Anti-Tumor Activity in Preclinical Models of Paclitaxel-Resistant, PIK3CA-Mutated Endometrial Cancer

Endometrial cancer stands as the predominant gynecological malignancy in developed nations. For advanced or recurrent disease, paclitaxel-based chemotherapy is the standard front-line therapy. However, paclitaxel resistance eternally develops. Based on the high prevalence of phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) mutation, reaching 50%, in endometrial cancer, we preclinically investigated the effectiveness of a combination of a phosphatidylinositol 3-kinase (PI3K) inhibitor with eribulin, a post-paclitaxel therapy for breast cancer, in treating paclitaxel-resistant, PIK3CA-mutated endometrial cancer. We generated paclitaxel-resistant cell lines from PIK3CA-mutated endometrial cancer cell lines by gradually increasing the concentration of paclitaxel in cell cultures. We observed that the PI3K/AKT and epithelial-mesenchymal transition (EMT) pathways in paclitaxel-resistant cells were significantly upregulated compared with those in parental cells. Then, we demonstrated that the combination of alpelisib (a PI3K inhibitor) and eribulin more effectively suppressed the cellular growth of paclitaxel-resistant cells in in vitro and in vivo xenograft models. Mechanistically, we demonstrated that the effect of the combination could be enhanced by inhibiting both the PI3K/AKT and EMT pathways. Therefore, we suggest that paclitaxel resistance is associated with the activation of the PIK3/AKT pathway in PIK3CA-mutated endometrial cancer, and the combination of a PI3K inhibitor and eribulin merits further clinical investigation.

New insights for gynecological cancer therapies: from molecular mechanisms and clinical evidence to future directions

Advanced and recurrent gynecological cancers lack effective treatment and have poor prognosis. Besides, there is urgent need for conservative treatment for fertility protection of young patients. Therefore, continued efforts are needed to further define underlying therapeutic targets and explore novel targeted strategies. Considerable advancements have been made with new insights into molecular mechanisms on cancer progression and breakthroughs in novel treatment strategies. Herein, we review the research that holds unique novelty and potential translational power to alter the current landscape of gynecological cancers and improve effective treatments. We outline the advent of promising therapies with their targeted biomolecules, including hormone receptor-targeted agents, inhibitors targeting epigenetic regulators, antiangiogenic agents, inhibitors of abnormal signaling pathways, poly (ADP-ribose) polymerase (PARP) inhibitors, agents targeting immune-suppressive regulators, and repurposed existing drugs. We particularly highlight clinical evidence and trace the ongoing clinical trials to investigate the translational value. Taken together, we conduct a thorough review on emerging agents for gynecological cancer treatment and further discuss their potential challenges and future opportunities.

B7-H3 confers stemness characteristics to gastric cancer cells by promoting glutathione metabolism through AKT/pAKT/Nrf2 pathway

BACKGROUND

Cancer stem-like cells (CSCs) are a small subset of cells in tumors that exhibit self-renewal and differentiation properties. CSCs play a vital role in tumor formation, progression, relapse, and therapeutic resistance. B7-H3, an immunoregulatory protein, has many protumor functions. However, little is known about the mechanism underlying the role of B7-H3 in regulating gastric cancer (GC) stemness. Our study aimed to explore the impacts of B7-H3 on GC stemness and its underlying mechanism.

METHODS

GC stemness influenced by B7-H3 was detected both in vitro and in vivo . The expression of stemness-related markers was examined by reverse transcription quantitative polymerase chain reaction, Western blotting, and flow cytometry. Sphere formation assay was used to detect the sphere-forming ability. The underlying regulatory mechanism of B7-H3 on the stemness of GC was investigated by mass spectrometry and subsequent validation experiments. The signaling pathway (Protein kinase B [Akt]/Nuclear factor erythroid 2-related factor 2 [Nrf2] pathway) of B7-H3 on the regulation of glutathione (GSH) metabolism was examined by Western blotting assay. Multi-color immunohistochemistry (mIHC) was used to detect the expression of B7-H3, cluster of differentiation 44 (CD44), and Nrf2 on human GC tissues. Student's t -test was used to compare the difference between two groups. Pearson correlation analysis was used to analyze the relationship between two molecules. The Kaplan-Meier method was used for survival analysis.

RESULTS

B7-H3 knockdown suppressed the stemness of GC cells both in vitro and in vivo . Mass spectrometric analysis showed the downregulation of GSH metabolism in short hairpin B7-H3 GC cells, which was further confirmed by the experimental results. Meanwhile, stemness characteristics in B7-H3 overexpressing cells were suppressed after the inhibition of GSH metabolism. Furthermore, Western blotting suggested that B7-H3-induced activation of GSH metabolism occurred through the AKT/Nrf2 pathway, and inhibition of AKT signaling pathway could suppress not only GSH metabolism but also GC stemness. mIHC showed that B7-H3 was highly expressed in GC tissues and was positively correlated with the expression of CD44 and Nrf2. Importantly, GC patients with high expression of B7-H3, CD44, and Nrf2 had worse prognosis ( P = 0.02).

CONCLUSIONS

B7-H3 has a regulatory effect on GC stemness and the regulatory effect is achieved through the AKT/Nrf2/GSH pathway. Inhibiting B7-H3 expression may be a new therapeutic strategy against GC.

PI3K/AKT/mTOR signaling transduction pathway and targeted therapies in cancer

The PI3K/AKT/mTOR (PAM) signaling pathway is a highly conserved signal transduction network in eukaryotic cells that promotes cell survival, cell growth, and cell cycle progression. Growth factor signalling to transcription factors in the PAM axis is highly regulated by multiple cross-interactions with several other signaling pathways, and dysregulation of signal transduction can predispose to cancer development. The PAM axis is the most frequently activated signaling pathway in human cancer and is often implicated in resistance to anticancer therapies. Dysfunction of components of this pathway such as hyperactivity of PI3K, loss of function of PTEN, and gain-of-function of AKT, are notorious drivers of treatment resistance and disease progression in cancer. In this review we highlight the major dysregulations in the PAM signaling pathway in cancer, and discuss the results of PI3K, AKT and mTOR inhibitors as monotherapy and in co-administation with other antineoplastic agents in clinical trials as a strategy for overcoming treatment resistance. Finally, the major mechanisms of resistance to PAM signaling targeted therapies, including PAM signaling in immunology and immunotherapies are also discussed.