EGFR-PI3K-AKT-mTOR signaling in head and neck squamous cell carcinomas: attractive targets for molecular-oriented therapy

Cell-vision fusion: A Swin transformer-based approach for predicting kinase inhibitor mechanism of action from Cell Painting data

Image-based profiling of the cellular response to drug compounds has proven effective at characterizing the morphological changes resulting from perturbation experiments. As data availability increases, however, there are growing demands for novel deep-learning methods. We applied the SwinV2 computer vision architecture to predict the mechanism of action of 10 kinase inhibitor compounds directly from Cell Painting images. This method outperforms the standard approach of using image-based profiles (IBP)-multidimensional feature set representations generated by bioimaging software. Furthermore, our fusion approach-cell-vision fusion, combining three different data modalities, images, IBPs, and chemical structures-achieved 69.79% accuracy and 70.56% F1 score, 4.20% and 5.49% higher, respectively, than the best-performing IBP method. We provide three techniques, specific to Cell Painting images, which enable deep-learning architectures to train effectively and demonstrate approaches to combat the significant batch effects present in large Cell Painting datasets.

Unveiling the nexus: Long non-coding RNAs and the PI3K/Akt pathway in oral squamous cell carcinoma

The PI3K/Akt pathway plays a critical role in the progression and treatment of oral squamous cell carcinoma (OSCC). Recent research has uncovered the involvement of long non-coding RNAs (lncRNAs) in regulating this pathway, influencing OSCC cell proliferation, survival, and metastasis. This review explores the latest findings on how certain lncRNAs act as either cancer promoters or cancer inhibitors within the PI3K/Akt signaling pathway. Certain lncRNAs act as oncogenic or tumor-suppressive agents, making them potential diagnostic and prognostic markers. Targeting these lncRNAs may lead to novel therapeutic strategies. The evolving fields of precision medicine and artificial intelligence promise advancements in OSCC diagnosis and treatment, enabling more personalized and effective patient care.

Importance of Autophagy Regulation in Glioblastoma with Temozolomide Resistance

Glioblastoma (GBM) is the most aggressive and common malignant and CNS tumor, accounting for 47.7% of total cases. Glioblastoma has an incidence rate of 3.21 cases per 100,000 people. The regulation of autophagy, a conserved cellular process involved in the degradation and recycling of cellular components, has been found to play an important role in GBM pathogenesis and response to therapy. Autophagy plays a dual role in promoting tumor survival and apoptosis, and here we discuss the complex interplay between autophagy and GBM. We summarize the mechanisms underlying autophagy dysregulation in GBM, including PI3K/AKT/mTOR signaling, which is most active in brain tumors, and EGFR and mutant EGFRvIII. We also review potential therapeutic strategies that target autophagy for the treatment of GBM, such as autophagy inhibitors used in combination with the standard of care, TMZ. We discuss our current understanding of how autophagy is involved in TMZ resistance and its role in glioblastoma development and survival.

Solanine Inhibits Proliferation and Angiogenesis and Induces Apoptosis through Modulation of EGFR Signaling in KB-ChR-8-5 Multidrug-Resistant Oral Cancer Cells

Background: The most important factors contributing to multi-drug resistance in oral cancer include overexpression of the EGFR protein and the downstream malignancy regulators that are associated with it. This study investigates the impact of solanine on inflammation, proliferation, and angiogenesis inhibition in multidrug-resistant oral cancer KB-Chr-8-5 cells through inhibition of the EGFR/PI3K/Akt/NF-κB signaling pathway. Methods: Cell viability was assessed using an MTT assay to evaluate cytotoxic effects. Production of reactive oxygen species (ROS), mitochondrial membrane potential (ΔΨM), and AO/EtBr staining were analyzed to assess apoptosis and mitochondrial dysfunction. Western blotting was employed to examine protein expression related to angiogenesis, apoptosis, and signaling pathways. Experiments were conducted in triplicate. Results: Solanine treatment at concentrations of 10, 20, and 30 μM significantly increased ROS production, which is indicative of its antioxidant properties. This increase was associated with decreased mitochondrial membrane potential (ΔΨM) with p < 0.05, suggesting mitochondrial dysfunction. Inhibition of EGFR led to reduced activity of PI3K, Akt, and NF-κB, resulting in decreased expression of iNOS, IL-6, Cyclin D1, PCNA, VEGF, Mcl-1, and HIF-1α and increased levels of the apoptotic proteins Bax, caspase-9, and caspase-3. These changes collectively inhibited the growth of multidrug-resistant (MDR) cancer cells. Conclusions: Solanine acts as a potent disruptor of cellular processes by inhibiting the EGFR-mediated PI3K/Akt/NF-κB signaling pathway. These results suggest that solanine holds promise as a potential preventive or therapeutic agent against multidrug-resistant cancers.

Gedunin modulates cellular growth and apoptosis in glioblastoma cell lines

BACKGROUND

Glioblastomas are characterized by aggressive behavior. Surgery, radiotherapy, and alkylating agents, including temozolomide are the most common treatment options for glioblastoma. Often, conventional therapies fail to treat these tumors since they develop drug resistance. There is a need for newer agents to combat this deadly tumor. Natural products such as gedunin have shown efficacy in several human diseases. A comprehensive study of gedunin, an heat shock protein (HSP)90 inhibitor, has not been thoroughly investigated in glioblastoma cell lines with different genetic modifications.

AIMS

A key objective of this study was to determine how gedunin affects the biological and signaling mechanisms in glioblastoma cells, and to determine how those mechanisms affect the proliferation and apoptosis of glioblastoma cells.

METHODS

The viability potentials of gedunin were tested using MTT, cell counts, and wound healing assays. Gedunin's effects on glioma cells were further validated using LDH and colony formation assays. In addition, we investigated the survival and apoptotic molecular signaling targets perturbed by gedunin using Western blot analysis and flow cytometry.

RESULTS

Our results show that there was a reduction in cell viability and inhibition of wound healing in the cells tested. Western blot analysis of the gene expression data revealed genes such as EGFR and mTOR/Akt/NF kappa B to be associated with gedunin sensitivity. Gedunin treatment induced apoptosis by cleaving poly ADP-ribose polymerase, activating caspases, and downregulating BCL-xL. Based on these results, gedunin suppressed cell growth and HSP client proteins, resulting in apoptosis in glioblastoma cell lines.

CONCLUSION

Our data provide in vitro support for the anticancer activity of gedunin in glioma cells by downregulating cancer survival proteins.

Photo-triggered caffeic acid delivery via psyllium polysaccharide- gellan gum-based injectable bionanogel for epidermoid carcinoma treatment

Here, the simultaneous effect of chemo- and photothermal therapy against epidermoid carcinoma (EC) was investigated. A novel hydrogel, termed bionanogel (BNG), was designed using psyllium mucilage polysaccharide and bacterial gellan gum, incorporated with nanocomplex carrying caffeic acid (CA) and IR-820, and further characterized. The dual effect of BNG and 808 nm laser (BNG + L) on EC was investigated. Staining and scratch assays were performed to analyze their therapeutic effect on EC. In vivo evaluations of BNG + L in xenograft models were performed. Rapid transition, limited swelling, degradability and high tensile strength indicated BNG stability and sustained drug release. Irradiation with 808 nm laser light at 1.25 W /cm2 for 4 min resulted in a temperature increase of 53 °C and facilitated cell ablation. The in vitro studies showed that BNG + L suppressed cancer progression via a late apoptotic effect. The in vivo study showed that the slow release of CA from BNG + L significantly attenuated EC with low mitotic index and downregulation of proteins involved in cancer proliferation such as EGFR, AKT, PI3K, ERK, mTOR and HIF-1α. Thus, BNG could be a novel medium for targeted and controlled drug delivery for the treatment of epidermoid cancer when triggered by NIR light.

Cell-Permeable Fluorescent Sensors Enable Rapid Live Cell Visualization of Plasma Membrane and Nuclear PIP3 Pools

Phosphoinositides, phospholipids that are key cell-signal mediators, are present at very low levels in cellular membranes and within nuclei. Phosphatidylinositol-(3,4,5)-trisphosphate (PIP3), a phosphoinositide barely present in resting cell membranes, is produced when cells receive either growth, proliferation, or movement signals. Aberrant PIP3 levels are associated with the formation of cancers. PIP3 pools are also present in the nucleus, specifically in the nucleolus. However, questions related to the organization and function of this lipid in such membraneless intranuclear structures remain unanswered. Therefore, chemical sensors for tracking cellular PIP3 are invaluable not only for timing signal initiation in membranes but also for identifying the organization and function of membraneless nuclear PIP3 pools. Because PIP3 is present in the inner leaflet of cell membranes and in the nucleus, cell-permeable, rapid-response fluorescent sensors would be ideal. We have designed two peptide-based, water-soluble, cell-permeable, ratiometric PIP3 sensors named as MFR-K17H and DAN-NG-H12G. MFR-K17H rapidly entered into the cell cytoplasm, distinctly reporting rapid (<1 min) time scales of growth factor-stimulated PIP3 generation and depletion within cell membranes in living cells. Importantly, MFR-K17H lighted up inherently high levels of PIP3 in triple-negative breast cancer cell membranes, implying future applications in the detection of enhanced PIP3 levels in cancerous cells. On the other hand, DAN-NG-H12G targeted intranuclear PIP3 pools, revealing that within membraneless structures, PIP3 resided in a hydrophobic environment. Together, both probes form a unique orthogonally targeted combination of cell-permeable, ratiometric probes that, unlike previous cell-impermeable protein-based sensors, are easy to apply and provide an unprecedented handle into PIP3-mediated cellular processes.

Molecular targeted therapies for cutaneous squamous cell carcinoma: recent developments and clinical implications

Cutaneous Squamous Cell Carcinoma (cSCC) is a common and potentially fatal type of skin cancer that poses a significant threat to public health and has a high prevalence rate. Exposure to ultraviolet radiation on the skin surface increases the risk of cSCC, especially in those with genetic syndromes like xerodermapigmentosum and epidermolysis bullosa. Therefore, understanding the molecular pathogenesis of cSCC is critical for developing personalized treatment approaches that are effective in cSCC. This article provides a comprehensive overview of current knowledge of cSCC pathogenesis, emphasizing dysregulated signaling pathways and the significance of molecular profiling. Several limitations and challenges associated with conventional therapies, however, are identified, stressing the need for novel therapeutic strategies. The article further discusses molecular targets and therapeutic approaches, i.e., epidermal growth factor receptor inhibitors, hedgehog pathway inhibitors, and PI3K/AKT/mTOR pathway inhibitors, as well as emerging molecular targets and therapeutic agents. The manuscript explores resistance mechanisms to molecularly targeted therapies and proposes methods to overcome them, including combination strategies, rational design, and optimization. The clinical implications and patient outcomes of molecular-targeted treatments are assessed, including response rates and survival outcomes. The management of adverse events and toxicities in molecular-targeted therapies is crucial and requires careful monitoring and control. The paper further discusses future directions for therapeutic advancement and research in this area, as well as the difficulties and constraints associated with conventional therapies.

Erlotinib combination with a mitochondria-targeted ubiquinone effectively suppresses pancreatic cancer cell survival

BACKGROUND

Pancreatic cancer is a leading cause of cancer-related deaths. Increased activity of the epidermal growth factor receptor (EGFR) is often observed in pancreatic cancer, and the small molecule EGFR inhibitor erlotinib has been approved for pancreatic cancer therapy by the food and drug administration. Nevertheless, erlotinib alone is ineffective and should be combined with other drugs to improve therapeutic outcomes. We previously showed that certain receptor tyrosine kinase inhibitors can increase mitochondrial membrane potential (Δψ_m), facilitate tumor cell uptake of Δψ_m-sensitive agents, disrupt mitochondrial homeostasis, and subsequently trigger tumor cell death. Erlotinib has not been tested for this effect.

AIM

To determine whether erlotinib can elevate Δψ_m and increase tumor cell uptake of Δψ_m-sensitive agents, subsequently triggering tumor cell death.

METHODS

Δψ_m-sensitive fluorescent dye was used to determine how erlotinib affects Δψ_m in pancreatic adenocarcinoma (PDAC) cell lines. The viability of conventional and patient-derived primary PDAC cell lines in 2D- and 3D cultures was measured after treating cells sequentially with erlotinib and mitochondria-targeted ubiquinone (MitoQ), a Δψ_m-sensitive MitoQ. The synergy between erlotinib and MitoQ was then analyzed using SynergyFinder 2.0. The preclinical efficacy of the two-drug combination was determined using immune-compromised nude mice bearing PDAC cell line xenografts.

RESULTS

Erlotinib elevated Δψ_m in PDAC cells, facilitating tumor cell uptake and mitochondrial enrichment of Δψ_m-sensitive agents. MitoQ triggered caspase-dependent apoptosis in PDAC cells in culture if used at high doses, while erlotinib pretreatment potentiated low doses of MitoQ. SynergyFinder suggested that these drugs synergistically induced tumor cell lethality. Consistent with in vitro data, erlotinib and MitoQ combination suppressed human PDAC cell line xenografts in mice more effectively than single treatments of each agent.

CONCLUSION

Our findings suggest that a combination of erlotinib and MitoQ has the potential to suppress pancreatic tumor cell viability effectively.

Recent drug design strategies and identification of key heterocyclic scaffolds for promising anticancer targets

Cancer, a noncommunicable disease, is the leading cause of mortality worldwide and is anticipated to rise by 75% in the next two decades, reaching approximately 25 million cases. Traditional cancer treatments, such as radiotherapy and surgery, have shown limited success in reducing cancer incidence. As a result, the focus of cancer chemotherapy has switched to the development of novel small molecule antitumor agents as an alternate strategy for combating and managing cancer rates. Heterocyclic compounds are such agents that bind to specific residues in target proteins, inhibiting their function and potentially providing cancer treatment. This review focuses on privileged heterocyclic pharmacophores with potent activity against carbonic anhydrases and kinases, which are important anticancer targets. Evaluation of ongoing pre-clinical and clinical research of heterocyclic compounds with potential therapeutic value against a variety of malignancies as well as the provision of a concise summary of the role of heterocyclic scaffolds in various chemotherapy protocols have also been discussed. The main objective of the article is to highlight key heterocyclic scaffolds involved in recent anticancer drug design that demands further attention from the drug development community to find more effective and safer targeted small-molecule anticancer agents.

Editorial of Special Issue "Oral Cancer: From Pathophysiology to Novel Therapeutic Approaches"

Oral squamous cell carcinoma (OSCC) is a heterogeneous type of malignancy that develops within the oral cavity comprising the lips, tongue, mouth floor, gums, and buccal mucosa, with more than 90% arising from the oral lining epithelium [...].

Cutaneous adverse reactions resulting from targeted cancer therapies: histopathologic and clinical findings

Targeted cancer treatments-designed to interfere with specific molecular signals responsible for tumor survival and progression-have shown benefit over conventional chemotherapies but may lead to diverse cutaneous adverse effects. This review highlights clinically significant dermatologic toxicities and their associated histopathologic findings, resulting from various targeted cancer drugs. Case reports and series, clinical trials, reviews, and meta-analyses are included for analysis and summarized herein. Cutaneous side effects resulting from targeted cancer therapies were reported with incidences as high as 90% for certain medications, and reactions are often predictable based on mechanism(s) of action of a given drug. Common and important reaction patterns included: acneiform eruptions, neutrophilic dermatoses, hand-foot skin reaction, secondary cutaneous malignancies, and alopecia. Clinical and histopathologic recognition of these toxicities remains impactful for patient care.

Therapeutic strategy for oncovirus-mediated oral cancer: A comprehensive review

Oral cancer is a neoplastic disorder of the oral cavities, including the lips, tongue, buccal mucosa, and lower and upper gums. Oral cancer assessment entails a multistep process that requires deep knowledge of the molecular networks involved in its progression and development. Preventive measures including public awareness of risk factors and improving public behaviors are necessary, and screening techniques should be encouraged to enable early detection of malignant lesions. Herpes simplex virus (HSV), human papillomavirus (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma-associated herpesvirus (KSHV) are associated with other premalignant and carcinogenic conditions leading to oral cancer. Oncogenic viruses induce chromosomal rearrangements; activate signal transduction pathways via growth factor receptors, cytoplasmic protein kinases, and DNA binding transcription factors; modulate cell cycle proteins, and inhibit apoptotic pathways. In this review, we present an up-to-date overview on the use of nanomaterials for regulating viral proteins and oral cancer as well as the role of phytocompounds on oral cancer. The targets linking oncoviral proteins and oral carcinogenesis were also discussed.

John M. Anticancer effects of thymoquinone in head and neck squamous cell carcinoma: A scoping review

Objective

Thymoquinone (TQ), the active constituent of Nigella sativa, has been shown to have anticancer effects in head and neck squamous cell carcinoma (HNSCC). This review aims to outline the properties of TQ, the known drivers in HNSCC formation, and summarize the anticancer effects of TQ in SCC.

Data Sources

Three databases (PubMed, Embase, and Google Scholar) were queried for the key words "thymoquinone squamous cell carcinoma."

Review Methods

Publications that were not original research and publications that did not have full-text available for review were excluded.

Results

Sixteen research articles met the inclusion criteria. Our review demonstrates that TQ-induced cytotoxicity is associated with increased expression and activity of the tumor suppressor p53, proapoptotic proteins Bax and caspases, as well as decreased expression and activity of antiapoptotic proteins Bcl-2 and Mdm2. Additionally, TQ modulates cell-survival pathways such as the PI3k/Akt pathway. TQ synergizes with therapeutics including cisplatin and radiation. Early TQ administration may prevent carcinogenesis via upregulation of antioxidant enzymes, and TQ administration in the presence of cancer can result in disease mitigation via induction of oxidative stress.

Conclusion

TQ acts as an upregulator of proapoptotic pathways and downregulator of antiapoptotic pathways, modulates the oxidative stress balance in tumor development, and works synergistically alongside other chemotherapeutics to increase cytotoxicity. TQ has the potential to prevent carcinogenesis in patients who are at high-risk for SCC and adjuvant treatment for SCC patients undergoing conventional treatments. Future studies should aim to identify specific populations in which TQ's effects would be the most beneficial.

Level of Evidence

Not available.

Tumour microenvironment and aberrant signaling pathways in cisplatin resistance and strategies to overcome in oral cancer

OBJECTIVE

Oral cancer is the sixteenth most prevalent cancer in the world and the third-most in India. Despite of several treatment modalities, the cure rate of oral cancer is still low due to drug resistance mechanisms, which are caused by many reasons. It is necessary to improve the existing treatment strategies and discover neoteric therapy to kill cancer cells, which will give oral cancer's cure rate more success. So this review aims to delineate the molecular mechanisms behind cisplatin resistance, specifically the role of the tumor microenvironment, extracellular vesicles, and altered signaling pathways and its overcoming strategies in oral cancer.

DESIGN

This review was designed by searching words like cancer, oral cancer, cisplatin-resistance, tumor microenvironment, aberrant signalings, and extracellular vesicles, overcoming strategies for cisplatin resistance in databases like PubMed, Google Scholar, web science, and Scopus. Data available in this review is from 2017 to 2021.

RESULTS

After searching too much data, we found these 98 data appropriate for our review. From these data, we found that tumor microenvironment, extracellular vesicles, and altered signaling pathways like PI3K/AKT, EGFR, NOTCH, Ras, PTEN, Nf-κβ, and Wnt signaling have a crucial role in resistance development towards cisplatin in oral cancer.

CONCLUSIONS

Lastly, this review explores the alternative strategies to overcome cisplatin resistance likely, the combination therapy and targeted therapy by combining more than one chemotherapeutic drug or inhibitors of signaling pathways and also by using nanoparticle loaded drugs that will reduce the drug efflux, which gives new treatment strategies.

Network Pharmacology and Molecular Docking Analyses Unveil the Mechanisms of Yiguanjian Decoction against Parkinson’s Disease from Inner/Outer Brain Perspective

Objective

This study aims to explore the pharmacodynamic mechanism of Yiguanjian (YGJ) decoction against Parkinson's disease (PD) through integrating the central nervous (inner brain) and peripheral system (outer brain) relationship spectrum.

Methods

The active components of YGJ were achieved from the TCMSP, TCMID, and TCM@Taiwan databases. The blood-brain barrier (BBB) permeability of the active components along with their corresponding targets was evaluated utilizing the existing website, namely, SwissADME and SwissTargetPrediction. The targets of PD were determined through database retrieval. The interaction network was constructed upon the STRING database, followed by the visualization using Cytoscape software. Then, we performed Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses on potential targets. Finally, the molecular docking approach was employed to assess the binding affinity between key components and key targets.

Results

Overall, we identified 79 active components, 128 potential targets of YGJ, and 97 potential targets of YGJ-BBB potentially suitable for the treatment of PD. GO and KEGG analyses showed that the YGJ treatment of PD mainly relied on PI3K-Akt pathway while the YGJ-BBB was mostly involved in endocrine resistance. The molecular docking results displayed high affinity between multiple compounds and targets in accordance with previous observations.

Conclusions

Our study unveiled the potential mechanisms of YGJ against PD from a systemic perspective: (1) for the YGJ, they have potential exerting effects on the peripheral system and inhibiting neuronal apoptosis through regulating the PI3K-Akt pathway; (2) for the YGJ-BBB, they can directly modulate endocrine resistance of the central nervous and holistically enhance body resistance to PD along with YGJ on PI3K-Akt pathway.

Polarized macrophages promote gestational beta cell growth through extracellular signal-regulated kinase 5 signalling

AIM

To show that depletion of pancreatic macrophages impairs gestational beta cell proliferation and leads to glucose intolerance.

MATERIALS AND METHODS

Genetic animal models were applied to study the effects of depletion of pancreatic macrophges on gestational beta-cell proliferaiton and glucose response. The crosstalk between macrophages and beta-cells was studied in vivo using beta-cell-specific extracellular-signal-regulated kinase 5 (ERK5) knockout and epidermal growth receptor (EGFR) knockout mice, and in vitro using a co-culture system.

RESULTS

Beta cell-derived placental growth factor (PlGF) recruited naïve macrophages and polarized them towards an M2-like phenotype. These macrophages then secreted epidermal growth factor (EGF), which activated extracellular signal-regulated kinase 5 (ERK5) signalling in beta cells to promote gestational beta cell proliferation. On the other hand, activation of ERK5 signalling in beta cells likely, in turn, enhanced the production and secretion of PlGF by beta cells.

CONCLUSIONS

Our study shows a regulatory loop between macrophages and beta cells through PlGF/EGF/ERK5 signalling cascades to regulate gestational beta cell growth.

LGALS3BP in Microglia Promotes Retinal Angiogenesis Through PI3K/AKT Pathway During Hypoxia

Purpose

Retinal microglia promote angiogenesis and vasculopathy in oxygen-induced retinopathy (OIR); however, its specific molecular mechanism in the formation of retinal angiogenesis remains unclear. The lectin galactoside-binding soluble 3 binding protein (LGALS3BP), a member of the scavenger receptor cysteine-rich (SRCR) domain protein family, is involved in tumor neovascularization, and we therefore hypothesized that LGALS3BP plays an active role in microglia-induced angiogenesis.

Methods

The expression of LGALS3BP in microglia was detected by immunofluorescence, RT-qPCR, and western blotting. Functional assays of human umbilical vein endothelial cells (HUVECs) such as migration, proliferation, and tube formation were measured by Transwell, EdU, and Matrigel assays. Angiogenesis-related factors and PI3K/AKT levels were detected by western blotting. The relationship between LGALS3BP and PI3K or HIF-1α was investigated by immunoprecipitation.

Results

Our results showed that the expression of LGALS3BP was significantly increased in microglia surrounding neovascularization of the OIR mice and was also upregulated in human microglial clone 3 (HMC3) cells after hypoxia. Moreover, HUVECs co-cultured with hypoxic HMC3 cells showed increased migration, proliferation, and tube formation, as well as levels of angiogenesis-related factor. However, the proangiogenic ability and angiogenesis-related factor expression of HMC3 cells was suppressed after silencing LGALS3BP. LGALS3BP induces the upregulation of angiogenesis-related factors through the PI3K/AKT pathway and then promotes angiogenesis in microglia.

Conclusions

Collectively, our findings suggest that LGALS3BP in microglia plays an important role in angiogenesis, suggesting a potential therapeutic target of LGALS3BP for angiogenesis.

Current and Emerging Molecular Therapies for Head and Neck Squamous Cell Carcinoma

Head and neck cancer affects nearly 750,000 patients, with more than 300,000 deaths annually. Advances in first line surgical treatment have improved survival rates marginally particularly in developed countries, however survival rates for aggressive locally advanced head and neck cancer are still poor. Recurrent and metastatic disease remains a significant problem for patients and the health system. As our knowledge of the genomic landscape of the head and neck cancers continues to expand, there are promising developments occurring in molecular therapies available for advanced or recalcitrant disease. The concept of precision medicine is underpinned by our ability to accurately sequence tumour samples to best understand individual patient genomic variations and to tailor targeted therapy for them based on such molecular profiling. Not only is their purported response to therapy a factor of their genomic variation, but so is their inclusion in biomarker-driven personalised medicine therapeutic trials. With the ever-expanding number of molecular druggable targets explored through advances in next generation sequencing, the number of clinical trials assessing these targets has significantly increased over recent years. Although some trials are focussed on first-line therapeutic approaches, a greater majority are focussed on locally advanced, recurrent or metastatic disease. Similarly, although single agent monotherapy has been found effective in some cases, it is the combination of drugs targeting different signalling pathways that seem to be more beneficial to patients. This paper outlines current and emerging molecular therapies for head and neck cancer, and updates readers on outcomes of the most pertinent clinical trials in this area while also summarising ongoing efforts to bring more molecular therapies into clinical practice.

Autoantibody-Specific Signalling in Pemphigus

Pemphigus is a severe autoimmune disease impairing barrier functions of epidermis and mucosa. Autoantibodies primarily target the desmosomal adhesion molecules desmoglein (Dsg) 1 and Dsg 3 and induce loss of desmosomal adhesion. Strikingly, autoantibody profiles in pemphigus correlate with clinical phenotypes. Mucosal-dominant pemphigus vulgaris (PV) is characterised by autoantibodies (PV-IgG) against Dsg3 whereas epidermal blistering in PV and pemphigus foliaceus (PF) is associated with autoantibodies against Dsg1. Therapy in pemphigus is evolving towards specific suppression of autoantibody formation and autoantibody depletion. Nevertheless, during the acute phase and relapses of the disease additional treatment options to stabilise desmosomes and thereby rescue keratinocyte adhesion would be beneficial. Therefore, the mechanisms by which autoantibodies interfere with adhesion of desmosomes need to be characterised in detail. Besides direct inhibition of Dsg adhesion, autoantibodies engage signalling pathways interfering with different steps of desmosome turn-over. With this respect, recent data indicate that autoantibodies induce separate signalling responses in keratinocytes via specific signalling complexes organised by Dsg1 and Dsg3 which transfer the signal of autoantibody binding into the cell. This hypothesis may also explain the different clinical pemphigus phenotypes.

Combinatorial treatment with Gefitinib and Bay11-7085 sensitizes primary Gefitinib-resistant OSCC cells by influencing the EGFR- NFκB signaling axis

EGFR-targeted therapies are reported to yield modest effect in OSCC. Activation of NFκB signaling is considered as molecular driver of EGFR inhibitor resistance in various cancers. In this scenario, present study focused on the molecular crosstalk between EGFR and NFκB signaling pathways and its therapeutic importance in OSCC. The EGFR- NFκB p65 co-expressed human OSCC cell lines UPCI:SCC066, UPCI:SCC040 and UM-SCC083B were used for in vitro studies. Recombinant human EGF, siRNAs, Western blot and qRT-PCR were used to dissect the molecular crosstalk between EGFR-NFκB signaling pathways in OSCCs. The effect of NFκB p65 knockdown on cancer hallmarks was studied by respective functional assays and RNA-Seq analysis was performed to identify the differentially expressed genes upon NFκB p65 knockdown. Gefitinib and Bay 11-7085 combination treatment was done to study the chemotherapeutic potential of EGFR- NFκB axis. Significant positive correlation between EGFR and NFκB p65 expression was observed in Head and Neck TCGA data set. EGFR induction or knockdown respectively stimulate or impair the NFκB signaling in EGFR- NFκB p65 co-expressed OSCC cell lines. NFκB p65 knockdown causes apoptosis and suppresses the viability, colony formation, migration, invasion, and spheroid formation. Using RNA-seq analysis, we identified PIK3CD as the NFκB target gene, which is commonly involved in these functions. Gefitinib and Bay 11-7085 combination treatment was found to be useful in chemosensitizing the Gefitinib-resistant OSCC cells by capitulating the EGFR- NFκB signaling axis. Combination treatment using Gefitinib and Bay 11-7085 enhanced the apoptosis and reduced cell viability and colony formation in a synergistic way. Our data demonstrated that EGFR-NFκB signaling axis plays a key role in the pathogenesis of OSCCs. Therefore, simultaneous therapeutic intervention of these pathways may be a good alternative approach for the management of OSCCs.

MiR-325 Promotes Oxaliplatin-Induced Cytotoxicity Against Colorectal Cancer Through the HSPA12B/PI3K/AKT/Bcl-2 Pathway

BACKGROUND

Oxaliplatin is one of the most effective chemotherapeutic drugs used for the treatment of colorectal cancer (CRC). However, intervention that attenuates the resistance of oxaliplatin is still required in the treatment of CRC.

AIMS

To investigate the role of miR-325 in changing the oxaliplatin sensitivity to CRC cells.

METHODS

Expression of miR-325 in colorectal cancer tissues and cell lines was measured by using qRT-PCR analysis. Cytotoxicity of oxaliplatin to control or miR-325-overexpressed HT29 and SW480 cells was evaluated by CCK-8 assays. Luciferase reporter assay was used to confirm the regulation of miR-325 on HSPA12B. Flow cytometry was performed to detect the mitochondrial membrane potential and cell apoptosis.

RESULTS

Expression of miR-325 was decreased in colorectal cancer tissues and cell lines. However, overexpression of miR-325 can decrease the 50% inhibiting concentration of oxaliplatin to colorectal cancer cell lines HT29 and SW480. Mechanically, we confirmed that miR-325 targeted HSPA12B in colorectal cancer. Therefore, overexpression of miR-325 inhibited the phosphorylation of PI3K and AKT and decreased the expression of Bcl-2 to promote the oxaliplatin-induced mitochondrial apoptosis in colorectal cancer.

CONCLUSIONS

MiR-325 sensitizes the colorectal cancer cells to oxaliplatin-induced cytotoxicity through the HSPA12B/PI3K/AKT/Bcl-2 pathway.

Molecular Pathways and Druggable Targets in Head and Neck Squamous Cell Carcinoma

Head and neck cancers are a heterogeneous group of neoplasms, affecting an ever increasing global population. Despite advances in diagnostic technology and surgical approaches to manage these conditions, survival rates have only marginally improved and this has occurred mainly in developed countries. Some improvements in survival, however, have been a result of new management and treatment approaches made possible because of our ever-increasing understanding of the molecular pathways triggered in head and neck oncogenesis, and the growing understanding of the abundant heterogeneity of this group of cancers. Some important pathways are common to other solid tumours, but their impact on reducing the burden of head and neck disease has been less than impressive. Other less known and little-explored pathways may hold the key to the development of potential druggable targets. The extensive work carried out over the last decade, mostly utilising next generation sequencing has opened up the development of many novel approaches to head and neck cancer treatment. This paper explores our current understanding of the molecular pathways of this group of tumours and outlines associated druggable targets which are deployed as therapeutic approaches in head and neck oncology with the ultimate aim of improving patient outcomes and controlling the personal and economic burden of head and neck cancer.

Overexpression of Notch2 enhances radiosensitivity via inhibition of the AKT/mTOR signaling pathway in nasopharyngeal carcinoma

Our previous study found that in nasopharyngeal carcinoma (NPC) cells, overexpression of Notch2 can inhibit epithelial-mesenchymal transition (EMT), which plays a vital role in mediating radiosensitivity. The purpose of this study was to explore the radiosensitizing efficacy of the Notch2 gene in NPC cells and its potential mechanism. We used the recombinant plasmid transfection technique to establish Notch2-overexpressing 5–8 F and CNE-2 NPC cells. Cell proliferation, radiosensitivity, apoptosis and cell cycle distribution were assessed by cell counting kit-8 (CCK-8) experiments, colony formation experiments and flow cytometry. The levels of proteins related to cell cycle, apoptosis, and the AKT/mTOR signaling pathway were evaluated by using Western blotting. The results suggested that Notch2 overexpression increased the radiosensitivity of NPC cells, with sensitizing enhancement ratios (SERs) of 1.24 (5–8 F cells) and 1.34 (CNE-2 cells). Flow cytometry indicated that the level of apoptosis and percentage of cells in G2/M-phase were highest in NPC cells overexpressing Notch2 and treated with radiotherapy compared to cells overexpressing Notch2 alone or administered radiotherapy alone. Western blotting showed that compared to that of cells treated with Notch2 overexpression or radiotherapy alone, the levels of γH2AX, Bax, Bcl-2, Cyclin D1 and AKT/mTOR signaling pathway-related proteins were modified in NPC cells overexpressing Notch2 and treated with radiotherapy. These findings showed that overexpression of Notch2 can increase the radiosensitivity of NPC cells by inhibiting the AKT/mTOR pathway.

Abbreviations

NPC: Nasopharyngeal carcinoma; EMT: Epithelial-mesenchymal transition; CCK8: Cell counting kit-8; EBV: Epstein-Barr virus; FBS: Fetal bovine serum; PE: Plating efficiency; SF: Survival fraction; SER: Sensitizing enhancement ratio; DSBs: DNA double-strand breaks

Inhibitory effect of gefitinib derivative LPY‑9 on human glioma

The present study aimed to investigate the effects of a gefitinib derivative, LPY-9, on the proliferation, apoptosis and migration of human glioma cell line U251-MG by CCK8, Transwell or flow cytometry, and the effect of LPY-9 on the activity of caspase-3 enzyme and related proteins in the vascular endothelial growth factor (VEGF) and epidermal growth factor receptor (EGFR) pathways by western blot and ELISA. It was found that LPY-9 exhibited higher a inhibitory effect on the proliferation of U251-MG cell lines compared with gefitinib and it also exhibited a certain dose-dependence. Following LPY-9 treatment, typical apoptotic morphology was observed under the microscope after Giemsa staining. LPY-9 induced apoptosis at low concentration, and the activity of caspase-3 enzyme increased with the increase in drug concentration, significantly inhibiting the secretion of VEGF in a dose-dependent manner. The effect was notably more evident compared with gefitinib at the same concentration. The expression level of caspase-3 and cleaved caspase-3 increased with the increase in LPY-9 concentration; however, expression levels of VEGF, EGFR, phosphorylated AKT and PI3K decreased with the increase of LPY-9 concentration and no change was observed in the expression level of AKT. LPY-9 inhibited the proliferation of the human glioma cell line U251-MG, promoted apoptosis and effectively inhibited the migration of U251-MG cells. The effect of LPY-9 was more noticeable compared with gefitinib. The results of the present study may provide a foundation for further study and clinical research of this as an anti-tumor drug in animal models.

Individual and Combined Treatments with Methylated Resveratrol Analogue DMU-214 and Gefitinib Inhibit Tongue Cancer Cells Growth via Apoptosis Induction and EGFR Inhibition

The methylated resveratrol analogue 3′-hydroxy-3,4,5,4′-tetramethoxystilbene (DMU-214) has been revealed to exert the anti-cancer activity by a block of the cell cycle at the G2/M phase, apoptosis induction, and metastasis inhibition. These biological events may be involved in crosstalk with the epidermal growth factor receptor (EGFR), which belongs to the ErbB family of receptor tyrosine kinases. Several cancer therapeutic approaches employ small molecules capable of inhibiting tyrosine kinases (e.g., gefitinib). According to more recent reports, combining gefitinib with chemotherapeutics, such as cisplatin, seems to be more effective than monotherapy. The present study aimed to assess the molecular mechanism of the potential anti-proliferative activity of individual and combined treatments with DMU-214 and gefitinib in SCC-25 and CAL-27 human tongue cancer cell lines. We showed for the first time the anti-cancer effects of DMU-214, gefitinib, and their combination in tongue cancer cells triggered via cell cycle arrest, apoptosis induction, and inhibition of the EGFR signaling pathway. The anti-proliferative effects of DMU-214 and gefitinib are also suggested to be related to the EGFR and EGFRP (phosphorylated epidermal growth factor receptor) expression status since we found significantly weaker cytotoxic activity of the compounds tested in SCC-25 cells, which overexpressed EGFR and EGFRP proteins.

Kallikrein-11, in Association with Coiled-Coil Domain Containing 25, as a Potential Prognostic Marker for Cholangiocarcinoma with Lymph Node Metastasis

Cholangiocarcinoma (CCA) is a malignancy arising from cholangiocytes. Currently, the treatment and prognosis for CCA are mostly poor. Recently, we have reported that coiled-coil domain containing 25 (CCDC25) protein level in the sera may be a diagnostic marker for CCA. Subsequently, we identified three binding proteins of CCDC25 and found that kallikrein-11 (KLK11) expression was highest among those binding proteins. In this study, we investigated CCDC25 and KLK11 expression in CCA and adjacent normal tissues (n = 18) using immunohistochemistry. The results demonstrated that the expressions of CCDC25 and KLK11 in CCA tissues were both significantly higher than the adjacent tissues (p < 0.001 and p = 0.001, respectively). Then, using GEPIA bioinformatics analysis, KLK11 mRNA was significantly overexpressed in CCA tumor tissues compared with normal tissues (p < 0.05). Moreover, CCDC25 expression was positively correlated with KLK11 expression in CCA with lymph node metastasis (p = 0.028, r = 0.593). An analysis for the interaction of KLK11 with CCDC25 and other proteins, using STRING version 11.0, revealed that CCDC25 and KLK11 correlated with metastasis-related proteins. In addition, Kaplan-Meier survival curve analysis revealed that a high expression of KLK11 was associated with the poor prognosis of CCA. In conclusion, KLK11 is, as a binding protein for CCDC25, possibly involved in the metastatic process of CCA. KLK11 may be used as a prognostic marker for CCA.

Deciphering the key heterocyclic scaffolds in targeting microtubules, kinases and carbonic anhydrases for cancer drug development

Heterocyclic scaffolds are widely utilized for drug design by taking into account the molecular structure of therapeutic targets that are related to a broad spectrum of ailments, including tumors. Such compounds display various covalent and non-covalent interactions with the specific residues of the target proteins while causing their inhibition. There is a substantial number of heterocyclic compounds approved for cancer treatment, and these compounds function by interacting with different therapeutic targets involved in tumorogenesis. In this review, we trace and emphasize the privileged heterocyclic pharmacophores that have immense potency against several essential chemotherapeutic tumor targets: microtubules, kinases and carbonic anhydrases. Potent compounds currently undergoing pre-clinical and clinical studies have also been assessed for ascertaining the effective class of chemical scaffolds that have significant therapeutic potential against multiple malignancies. In addition, we also describe briefly the role of heterocyclic compounds in various chemotherapy regimens. The optimized molecular hybridization of delineated motifs may result in the discovery of more active anticancer therapeutics and circumvent the development of resistance by specific targets in the future.

Pepsin Promotes Activation of Epidermal Growth Factor Receptor and Downstream Oncogenic Pathways, at Slightly Acidic and Neutral pH, in Exposed Hypopharyngeal Cells

Pepsin refluxate is considered a risk factor for laryngopharyngeal carcinogenesis. Non-acidic pepsin was previously linked to an inflammatory and tumorigenic effect on laryngopharyngeal cells in vitro. Yet there is no clear evidence of the pepsin-effect on a specific oncogenic pathway and the importance of pH in this process. We hypothesized that less acidic pepsin triggers the activation of a specific oncogenic factor and related-signalling pathway. To explore the pepsin-effect in vitro, we performed intermittent exposure of 15 min, once per day, for a 5-day period, of human hypopharyngeal primary cells (HCs) to pepsin (1 mg/mL), at a weakly acidic pH of 5.0, a slightly acidic pH of 6.0, and a neutral pH of 7.0. We have documented that the extracellular environment at pH 6.0, and particularly pH 7.0, vs. pH 5.0, promotes the pepsin-effect on HCs, causing increased internalized pepsin and cell viability, a pronounced activation of EGFR accompanied by NF-κB and STAT3 activation, and a significant upregulation of EGFR, AKT1, mTOR, IL1β, TNF-α, RELA(p65), BCL-2, IL6 and STAT3. We herein provide new evidence of the pepsin-effect on oncogenic EGFR activation and its related-signaling pathway at neutral and slightly acidic pH in HCs, opening a window to further explore the prevention and therapeutic approach of laryngopharyngeal reflux disease.

Transcriptional Repression of MFG-E8 Causes Disturbance in the Homeostasis of Cell Cycle Through DOCK/ZP4/STAT Signaling in Buffalo Mammary Epithelial Cells

The mammary gland is a unique apocrine gland made up of a branching network of ducts that end in alveoli. It is an ideal system to study the molecular mechanisms associated with cell proliferation, differentiation, and oncogenesis. MFG-E8, also known as Lactadherin, is a vital glycoprotein related to the milk fat globule membrane and initially identified to get secreted in bovine milk. Our previous report suggests that a high level of MFG-E8 is indicative of high milk yield in dairy animals. Here, we showed that MFG-E8 controls the cell growth and morphology of epithelial cells through a network of regulatory transcription factors. To understand the comprehensive action, we downregulated its expression in MECs by MFG-E8 specific shRNA. We generated a knockdown proteome profile of differentially expressed proteins through a quantitative iTRAQ experiment on a high-resolution mass spectrometer (Q-TOF). The downregulation of MFG-E8 resulted in reduced phagocytosis and cell migration ability, whereas it also leads to more lifespan to knockdown vis-a-vis healthy cells, which is confirmed through BrdU, MTT, and Caspase 3/7. The bioinformatics analysis revealed that MFG-E8 knockdown perturbs a large number of intracellular signaling, eventually leading to cessation in cell growth. Based on the directed network analysis, we found that MFG-E8 is activated by CX3CL1, TP63, and CSF2 and leads to the activation of SOCS3 and CCL2 for the regulation of cell proliferation. We further proved that the depletion of MFG-E8 resulted in activated cytoskeletal remodeling by MFG-E8 knockdown, which results in the activation of three independent pathways ZP4/JAK-STAT5, DOCK1/STAT3, and PIP3/AKT/mTOR. Overall, this study suggests that MFG-E8 expression in mammary epithelial cells is an indication of intracellular deterioration in cell health. To date, to the best of our knowledge, this is the first study that explores the downstream targets of MFG-E8 involved in the regulation of mammary epithelial cell health.

Assessment of multiple pathways involved in the inhibitory effect of HCG22 on oral squamous cell carcinoma progression

LncRNAs have been proposed to be associated with the tumorigenesis and progression of oral squamous cell carcinoma (OSCC). LncRNA HLA complex group 22 (HCG22) was reported to be lowly expressed and associated with poor prognosis in head and neck squamous cell carcinoma (HNSCC). However, the biological role and related mechanism of HCG22 in OSCC have not been characterized. HCG22 expression in OSCC cells was detected by qRT-PCR. Cell proliferation, invasion, and apoptosis were evaluated by Bromodeoxyuridine (BrdU) proliferation assay, Transwell invasion assay, and flow cytometry analysis, respectively. The protein levels of proliferating cell nuclear antigen (PCNA), E-cadherin, Vimentin, Bcl-2, Bax, protein kinase B (Akt), phosphorylated Akt (p-Akt), mammalian target of rapamycin (mTOR), phosphorylated mTOR (p-mTOR), and β-catenin were detected by western blot. Cell growth evaluation was performed using in vitro colony formation assay and in vivo tumor xenograft assay. We found that HCG22 was weakly expressed in OSCC cells. HCG22 overexpression inhibited cell proliferation and invasion and induced apoptosis in OSCC cells. The levels of PCNA, Vimentin, and Bcl-2 were decreased and E-cadherin and Bax expression was elevated in OSCC cells after HCG22 overexpression. Additionally, HCG22 overexpression inhibited the Akt, mTOR and Wnt/β-catenin pathways. Activation of Akt, mTOR, and Wnt/β-catenin pathways attenuated the anti-tumor property of HCG22 in OSCC cells. Furthermore, HCG22 overexpression inhibited the growth of OSCC cells in vitro and in vivo. In conclusion, HCG22 exerted anti-tumor property in OSCC by inhibiting the Akt, mTOR, and Wnt/β-catenin pathways.

Thymoquinone loaded calcium alginate and polyvinyl alcohol carrier inhibits the 7,12-dimethylbenz[a]anthracene-induced hamster oral cancer via the down-regulation of PI3K/AKT/mTOR signaling pathways

Oral cancer is a multifactorial cancer that affects millions of peoples worldwide. The current exploration aimed to evaluate the mechanisms that thymoquinone nanoencapsulated carrier and its effects on 7,12-Dimethylbenz[a]anthracene (DMBA) stimulated hamster buccal pouch cancer in Syrian hamster model. Nanocarrier was characterized by SEM, TEM, FTIR analysis. The incidence of tumor, and biochemicals makers was studied through standard methods. The mRNA expression level of inflammatory markers NF-κBp50, NF-κBp65, and PI3K/AKT/mTOR markers in the buccal tissues of control and experimental animals were investigated through RT-PCR analysis. In thymoquinone (TQ) loaded calcium alginate and polyvinyl alcohol carrier (TQ/Ca-alg-PVA) no squamous cell carcinogenesis developed and others moderate dysplasia revealed differentiated form of hyperplasia and keratosis. In biochemical analyses with DMBA + TQ/Ca-alg-PVA (20 mg/kg bw) orally administered hamsters showed restored the antioxidants, detoxification, xenobiotic metabolising enzymes in DMBA induced plasma and oral tissues of hamsters. Further, mRNA expression level of NF-κBp50/p65 and PI3K/AKT/mTOR were upregulated in the DMBA alone painted hamster. In contrast, these expressions were down regulated in orally TQ/Ca-alg-PVA treated experimental animals. This ability more eligible to deregulate the inflammatory and PI3K/AKT/mTOR signaling pathway that proved it suppresses anti-invasion/metastasis activity during hamster buccal pouch carcinogenesis. From this study, we recommended that TQ/Ca-alg-PVA has documented as effective chemopreventive agents, in further many molecular machineries need to study.

PI3k inhibitors (BKM120 and BYL719) as radiosensitizers for head and neck squamous cell carcinoma during radiotherapy

Approximately 500,000 new cases of head and neck squamous cell carcinoma (HNSCC) are reported annually. Radiation therapy is an important treatment for oral squamous cell carcinoma (OSCC). The survival rate of patients with HNSCC remained low (50%) in decades because of radiation therapy failure caused by the radioresistance of HNSCC cells. This study aimed to identify PI3K inhibitors that can enhance radiosensitivity. Results showed that pan-Phosphoinositide 3-kinases (PI3K) inhibitor BKM120 and class I α-specific PI3K inhibitor BYL719 dose-dependently reduced the growth of OSCC cells but not that of radioresistant OML1-R cells. The combination treatment of BKM120 or BYL719 with radiation showed an enhanced inhibitory effect on OSCC cells and radioresistant OML1-R cells. Furthermore, the enhanced inhibitory effect of the combination treatment was confirmed in patient-derived OSCC cells. The triple combination treatment of mTOR inhibitor AZD2014 and BKM120 or AZD2014 and BYL719 with radiation showed a significantly enhanced inhibitory effect on radioresistant OML1-R cells. These results suggest that the PI3K inhibitors are potential therapeutic agents with radiosensitivity for patients with OSCC.

Assessment of colon cancer molecular mechanism: a system biology approach

AIM

The current study aimed to assess and compare colon cancer dysregulated genes from the GEO and STRING databases.

BACKGROUND

Colorectal cancer is known as the third most common kind of cancer and the second most important reason for global cancer-related mortality rates. There have been many studies on the molecular mechanism of colon cancer.

METHODS

From the STRING database, 100 differentially expressed proteins related to colon cancers were retrieved and analyzed by network analysis. The central nodes of the network were assessed by gene ontology. The findings were compared with a GSE from GEO.

RESULTS

Based on data from the STRING database, TP53, EGFR, HRAS, MYC, AKT1, GAPDH, KRAS, ERBB2, PTEN, and VEGFA were identified as central genes. The central nodes were not included in the significant DEGs of the analyzed GSE.

CONCLUSION

A combination of different database sources in system biology investigations provides useful information about the studied diseases.

Epstein-Barr Virus-Oral Bacterial Link in the Development of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is the most common type of oral cancer. Its development has been associated with diverse factors such as tobacco smoking and alcohol consumption. In addition, it has been suggested that microorganisms are risk factors for oral carcinogenesis. Epstein-Barr virus (EBV), which establishes lifelong persistent infections and is intermittently shed in the saliva, has been associated with several lymphomas and carcinomas that arise in the oral cavity. In particular, it has been detected in a subset of OSCCs. Moreover, its presence in patients with periodontitis has also been described. Porphyromonas gingivalis (P. gingivalis) is an oral bacterium in the development of periodontal diseases. As a keystone pathogen of periodontitis, P. gingivalis is known not only to damage local periodontal tissues but also to evade the host immune system and eventually affect systemic health. Persistent exposure to P. gingivalis promotes tumorigenic properties of oral epithelial cells, suggesting that chronic P. gingivalis infection is a potential risk factor for OSCC. Given that the oral cavity serves as the main site where EBV and P. gingivalis are harbored, and because of their oncogenic potential, we review here the current information about the participation of these microorganisms in oral carcinogenesis, describe the mechanisms by which EBV and P. gingivalis independently or synergistically can collaborate, and propose a model of interaction between both microorganisms.

Dacomitinib and gedatolisib in combination with fractionated radiation in head and neck cancer

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We evaluated radiation with dual EGFR and PI3K targeting in head and neck cancer.

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Dacomitinib, showed an inverse correlation between growth inhibition and EGFR expression.

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Gedatolisib was effective in each cell line. Neither drug caused radiosensitization in vitro.

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Gedatolisib was relatively ineffective in vivo in combination with dacomitinib and/or radiation.

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Dacomitinib was highly effective alone and in combination with radiation and/or gedatolisib.

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Immunoblotting studies in vivo mirrored the effects seen with growth delay.

Background and purpose

There has been little success targeting individual genes in combination with radiation in head and neck cancer. In this study we investigated whether targeting two key pathways simultaneously might be more effective.

Materials and methods

We studied the effect of combining dacomitinib (pan-HER, irreversible inhibitor) and gedatolisib (dual PI3K/MTOR inhibitor) with radiation in well characterized, low passage xenograft models of HNSCC in vitro and in vivo.

Results

Dacomitinib showed differential growth inhibition in vitro that correlated to EGFR expression whilst gedatolisib was effective in both cell lines. Neither agent radiosensitized the cell lines in vitro. In vivo studies demonstrated that dacomitinib was an effective agent alone and in combination with radiation whilst the addition of gedatolisib did not enhance the effect of these two modalities despite inhibiting phosphorylation of key genes in the PI3K/MTOR pathway.

Conclusions

Our results showed that combining two drugs with radiation provided no added benefit compared to the single most active drug. Dacomitinib deserves more investigation as a radiation sensitizing agent in HNSCC.

HS-173, a selective PI3K inhibitor, induces cell death in head and neck squamous cell carcinoma cell lines

BACKGROUND

The selective PI3K (Phosphatidylinositol 3-kinase) inhibitor HS-173 has anticancer activity in non-small cell lung cancer and pancreatic cancer cells. Of all head and neck squamous cell carcinomas (HNSCC) 20% harbor specific mutations in the genome. The aim of this study was to investigate the effect of HS-173 on HNSCC cell lines.

METHODS

The cell lines SCC25, CAL27 and FaDu were incubated with HS-173. Its antiproliferative effect was determined using the CCK‑8 cell proliferation assay. Combined incubation with cisplatin was performed and combination index analysis was conducted. To investigate its effect on radiotherapy, cells were irradiated with 2, 4, 6 and 8 Gy, respectively. Synergistic effects of radiation and HS-173 were measured by proliferation assays and clonogenic survival.

RESULTS

The use of HS-173 induced significant reduction of cell proliferation across all cell lines. Most interestingly, it showed a synergistic effect with cisplatin treatment. Clonogenic survival revealed a radiosensitizing effect in CAL27 and FaDu cells. The HS-173 caused significant induction of apoptosis in SCC25 and FaDu cells.

CONCLUSION

The selective PI3K inhibitor HS-173 is a potent chemosensitizing and also radiosensitizing drug in treatment of HNSCC cell lines and could be an effective treatment in PI3K-mutated HNSCC.

Salicylate sensitizes oral squamous cell carcinoma to chemotherapy through targeting mTOR pathway

Oral squamous cell carcinoma (OSCC) is an extremely aggressive neoplasm, which is usually diagnosed in the advanced stage of the disease. Extensive studies have shown a link between chronic inflammation and various types of cancer, including OSCC. Salicylate is a biotransformation product of aspirin, with similar anti-inflammatory ability to aspirin but lacks aspirin's inhibitory effect on the isolated cyclooxygenase activity. Our study indicates that salicylate sensitizes OSCC to anti-cancer drugs, but the mechanisms of its action are unclear. Here, OSCC cells were used to evaluate the cytotoxicity of salicylate alone or in combination with cisplatin (CDDP). RPPA proteomic array and Western blotting were employed to determine the signaling pathways affected by salicylate. Salicylate decreased cell survival rate and induced cell apoptosis in OSCC cells but not human normal oral mucosal epithelial cells (hTERT-OME). The use of sodium salicylate (SS) dramatically sensitized OSCC cells to CDDP. RPPA array showed that SS reduced many oncogenes such as PI3K/mTOR signaling and cancer stem cell (CSC)-related genes versus control. Western and transcriptional analyses substantiated that salicylate down-regulated these CSC-associated genes and the mTOR pathway dose dependently. Salicylate preferentially repressed the ability of sorted ALDH1+ cells to form tumor spheres. Finally, salicylate suppressed tumor growth in vivo, and the combination of salicylate and CDDP further synergistically reduced the growth of tumors. Salicylate hinders OSCC cell growth and sensitizes OSCC cells to CDDP through targeting CSCs and the mTOR signaling pathway. We propose that salicylate is beneficial for OSCC patients, and salicylate may be combined with chemotherapies to effectively treat OSCC patients.

The Potential of Phytochemicals in Oral Cancer Prevention and Therapy: A Review of the Evidence

The etiological factors of oral cancer are complex including drinking alcohol, smoking tobacco, betel quid chewing, human papillomavirus infection, and nutritional deficiencies. Understanding the molecular mechanism of oral cancer is vital. The traditional treatment for patients with oral squamous cell carcinoma (e.g., surgery, radiotherapy, and chemotherapy) and targeted molecular therapy still have numerous shortcomings. In recent years, the use of phytochemical factors to prevent or treat cancer has received increasing attention. These phytochemicals have little or no toxicity against healthy tissues and are thus ideal chemopreventive agents. However, phytochemicals usually have low water solubility, low bioavailability, and insufficient targeting which limit therapeutic use. Numerous studies have investigated the development of phytochemical delivery systems to address these problems. The present article provides an overview of oral cancer including the etiological factors, diagnosis, and traditional therapy. Furthermore, the classification, dietary sources, anticancer bioactivity, delivery system improvements, and molecular mechanisms against oral cancer of phytochemicals are also discussed in this review.

The biological activities of the spiderworts (Tradescantia)

Widely used throughout the world as traditional medicine for treating a variety of diseases ranging from cancer to microbial infections, members of the Tradescantia genus show promise as sources of desirable bioactive compounds. The bioactivity of several noteworthy species has been well-documented in scientific literature, but with nearly seventy-five species, there remains much to explore in this genus. This review aims to discuss all the bioactivity-related studies of Tradescantia plants and the compounds discovered, including their anticancer, antimicrobial, antioxidant, and antidiabetic activities. Gaps in knowledge will also be identified for future research opportunities.

Phosphorylated GSK‑3β protects stress‑induced apoptosis of myoblasts via the PI3K/Akt signaling pathway

Facial jaw muscle is involved in the occurrence, development, treatment and maintenance of maxillofacial deformities. The structure and function of this tissue can be altered by changes in external stimuli, and orthodontists can regulate its reconstruction using orthopedic forces. The PI3K/Akt signaling pathway is most well‑known for its biological functions in cell proliferation, survival and apoptosis. In the present study, the effects of the PI3K/Akt signaling pathway in cyclic stretch‑induced myoblast apoptosis were investigated. For this purpose, L6 rat myoblasts were cultured under mechanical stimulation and treated with the PI3K kinase inhibitor, LY294002, to elucidate the role of the PI3K/Akt signaling pathway. Cells were stained with Hoechst 33258 to visualize morphological changes and apoptosis of myoblasts, and western blotting was performed to detect expression of Akt, phosphorylated (p)‑Akt (Ser473), glycogen synthase kinase 3β (GSK‑3β) and p‑GSK‑3β (Ser9). After addition of PI3K inhibitor, the expression of total Akt and GSK‑3β did not significantly differ among groups; however, the levels of p‑Akt and p‑GSK‑3β were lower in inhibitor‑treated groups than in those treated with loading stress alone. In addition, the rate of apoptosis in myoblasts subjected to cyclic stretch increased in a time‑dependent manner, peaking at 24 h. Collectively, it was also demonstrated that the PI3K/Akt/GSK‑3β pathway plays an important role in stretch‑induced myoblast apoptosis.

Extracellular Vesicle Activation of Latent HIV-1 Is Driven by EV-Associated c-Src and Cellular SRC-1 via the PI3K/AKT/mTOR Pathway

HIV-1 is a global health crisis that has infected more than 37 million people. Latent reservoirs throughout the body are a major hurdle when it comes to eradicating the virus. In our previous study, we found that exosomes, a type of extracellular vesicle (EV), from uninfected cells activate the transcription of HIV-1 in latent infected cells, regardless of combination antiretroviral therapy (cART). In this study, we investigated the specific mechanism behind the EV activation of latent HIV-1. We found that phosphorylated c-Src is present in EVs of various cell lines and has the ability to activate downstream proteins such as EGFR, initiating a signal cascade. EGFR is then able to activate the PI3K/AKT/mTOR pathway, resulting in the activation of STAT3 and SRC-1, culminating in the reversal of HIV-1 latency. This was verified by examining levels of HIV-1 TAR, genomic RNA and HIV-1 Gag p24 protein in cell lines and primary cells. We found that EVs containing c-Src rescued HIV-1 despite the presence of inhibitors, validating the importance of EV-associated c-Src in latent HIV-1 activation. Lastly, we discovered an increased recruitment of p300 and NF-κB in the nucleus of EV-treated infected cells. Collectively, our data suggest that EV-associated c-Src is able to activate latent HIV-1 via the PI3K/AKT/mTOR pathway and SRC-1/p300-driven chromatin remodeling. These findings could aid in designing new strategies to prevent the reactivation of latent HIV-1 in patients under cART.

Cetuximab enhances oridonin-induced apoptosis through mitochondrial pathway and endoplasmic reticulum stress in laryngeal squamous cell carcinoma cells

Cetuximab plus oridonin showed a synergistic way to kill laryngeal squamous cell carcinoma (LSCC), as been reported previously. The present work further mechanistically extended action of the synergistic effects of combination treatment. Firstly, two LSCC cells displayed higher sensitivity to oridonin, whereas both low EGFR expression tumor cells and EGFR knockdown LSCC cells were less sensitive to oridonin. Next, cetuximab/oridonin significantly enhanced the mitochondrial apoptosis through NF-κB. Meanwhile, PI3K/Akt and JAK2/STAT3 pathways are associated with the nucleus translocation of NF-κB by combination treatment. Additionally, cetuximab enhanced oridonin-promoted ER stress-related apoptosis. Interestingly, both ER stress and mitochondrial apoptosis by combination treatment are abrogated by ROS scavenger. Furthermore, oridonin/cetuximab induced ROS production after 1.5 h, followed by G2/M arrest and apoptosis, indicating that ROS generation might be an early and key event. Taken together, cetuximab enhances oridonin-induced ER stress and mitochondrial apoptotic pathway, which contributes to the synergistic antitumor effects of cetuximab/oridonin.

Downregulation of CLDN6 inhibits cell proliferation, migration, and invasion via regulating EGFR/AKT/mTOR signalling pathway in hepatocellular carcinoma

Accumulating evidence showed that the claudin-6 (CLDN6) expression was abnormal in many cancers, while its expression and biological functions in hepatocellular carcinoma (HCC) is still unclear. The present study demonstrated that CLDN6 was upregulated in HCC tissues compared with tumour-adjacent tissues. CLDN6 silencing was significantly inhibited proliferation, migration, and invasion of HepG2 cells. Meanwhile, downregulation of CLDN6 remarkably inhibited the activation of EGFR/AKT/mTOR signalling pathway. Interestingly, the effect of CLDN6 overexpression on HepG2 cell proliferation and invasion could be inhibited by EGFR/AKT/mTOR signalling pathway inhibitor (AG1478). SIGNIFICANCE OF THE STUDY: These findings suggested that CLDN6 may act as an oncogene in HCC and improve HepG2 cell proliferation, migration, and invasion may via EGFR/AKT/mTOR signalling pathway.

Osthole induces cell cycle arrest and apoptosis in head and neck squamous cell carcinoma by suppressing the PI3K/AKT signaling pathway

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most common lethal tumors with a high recurrence rate and low survival rate. Therefore, an urgent need exists for novel and effective treatment strategies for HNSCC patients.

METHODS

Osthole, a natural ingredient extracted from Cnidium monnieri (L.) 'Cusson', has multiple pharmacological effects including antineoplastic activity. Regrettably, the antineoplastic effect of osthole in HNSCC cells remains undefined. We utilize in vitro assays to assess the anti-proliferative effects of osthole in HNSCC cells and tumorigenesis assays using FaDu cells in murine HNSCC models to assess in vivo function. Moreover, the possible molecular mechanisms of Osthole on HNSCC cells was also investigated.

RESULTS

Our findings show that the anti-proliferation effect of osthole might function through induction of cell cycle arrest (G2/M phase) and apoptosis in HNSCC. Osthole could also down-regulating the protein level of cell cycle and apoptosis related proteins, such as Bcl-2, PARP1, Survivin, CyclinB1 and Cdc2, while up-regulating expression of Cleaved Caspase3/9, Cleaved PARP1 and Bax. Similarly, osthole suppressed the in vivo growth of FaDu cells in a subcutaneous tumor model. In terms of mechanism, our data show that osthole can suppress the PI3K/AKT pathway.

CONCLUSIONS

In the current study, our in vitro and in vivo assay showed the suppressive effect of Osthole on HNSCC cells through induce cell cycle arrest (G2/M phase) and apoptosis. Moreover, the action mechanisms of Osthole on proliferation related signaling pathways was disclosed. Our present study suggests that osthole might be used as an effective therapeutic agent for patients with HNSCC.

eIF4E and 4EBP1 are prognostic markers of head and neck squamous cell carcinoma recurrence after definitive surgery and adjuvant radiotherapy

There is high risk of metastasis and recurrence in head and neck squamous cell carcinoma (HNSCC) patients, especially for patient who received definitive surgery and adjuvant radiotherapy. Aberrant activation of PI3K/AKT/mTOR signaling occurs in approximately 80% of HNSCC, which has been indicated to serve as prognostic biomarkers for patients suffer from recurrence or metastasis. Therefore, in this study, we focus on the relationship between the expression level of signaling factors in PI3K/AKT/mTOR pathway and recurrence tumor from HNSCC patients. A tissue microarray (TMA) was constructed from 54 cases of HNSCC patients who received definitive surgery and adjuvant radiotherapy, are followed more than 5 years, and with no previous malignancy and synchronous tumor. Slides were scored and dichotomized by two pathologists and scores. Based on the TMA block with IHC staining, the results showed that PI3K/AKT/mTOR signaling was highly activated both in recurrence and non-recurrence patients. Particularly, in the recurrence population, the results showed the low expression phospho-eukaryotic initiation factor 4E (p-eIF4E) or high expression eIF4E, phospho-eIF4E binding protein 1 (p-4EBP1), phospho-ribosomal protein S6 kinase beta-1 (p-S6K1) and phospho-40S ribosomal protein S6 (p-S6R) exhibited worse overall survival. The expression level of eIF4E and p-4EBP1 were significantly associated with tumor recurrence and recurrence-free survival. Furthermore, high expression level of eIF4E and p-4EBP1 had worse recurrence-free survival. In conclusion, the expression of eIF4E and p-4EBP1 should be considered as predictive biomarkers for the HNSCC patients. This may contribute to potential predictive biomarkers for HNSCC patient who receive adjuvant radiotherapy.

Increased LGALS3BP promotes proliferation and migration of oral squamous cell carcinoma via PI3K/AKT pathway

Previous studies showed that lectin galactoside-binding soluble 3 binding protein (LGALS3BP) is an important participant in tumor progression. However, its prognostic value and functional mechanism in oral squamous cell carcinoma (OSCC) are still unclear. In this study, we analyzed LGALS3BP expression in OSCC tissues via Oncomine databases and immunohistochemical staining. LGALS3BP was significantly up-regulated in OSCC tumor tissues. IHC analysis showed that LGALS3BP was predominantly expressed in tumor cells and correlated with poor clinical characteristics. In addition, high LGALS3BP expression predicted poor clinical outcomes and multivariate analysis revealed that LGALS3BP expression was as an independent prognostic factor for OS, DFS and RFS (p < .0001, p = .002, p = .002). Mechanically, LGALS3BP regulated OSCC proliferation and migration via PI3K/AKT pathways, which was abrogated by PI3K inhibitor LY294002 in a dose-dependent manner. Our results suggested that LGALS3BP could be served as a novel independent prognostic factor as well as a potential therapeutic target for OSCC treatment.

SHP2 Inhibition Overcomes RTK-Mediated Pathway Reactivation in KRAS-Mutant Tumors Treated with MEK Inhibitors

FGFR1 was recently shown to be activated as part of a compensatory response to prolonged treatment with the MEK inhibitor trametinib in several KRAS-mutant lung and pancreatic cancer cell lines. We hypothesize that other receptor tyrosine kinases (RTK) are also feedback-activated in this context. Herein, we profile a large panel of KRAS-mutant cancer cell lines for the contribution of RTKs to the feedback activation of phospho-MEK following MEK inhibition, using an SHP2 inhibitor (SHP099) that blocks RAS activation mediated by multiple RTKs. We find that RTK-driven feedback activation widely exists in KRAS-mutant cancer cells, to a less extent in those harboring the G13D variant, and involves several RTKs, including EGFR, FGFR, and MET. We further demonstrate that this pathway feedback activation is mediated through mutant KRAS, at least for the G12C, G12D, and G12V variants, and wild-type KRAS can also contribute significantly to the feedback activation. Finally, SHP099 and MEK inhibitors exhibit combination benefits inhibiting KRAS-mutant cancer cell proliferation in vitro and in vivo These findings provide a rationale for exploration of combining SHP2 and MAPK pathway inhibitors for treating KRAS-mutant cancers in the clinic.

Sodium butyrate induces autophagic apoptosis of nasopharyngeal carcinoma cells by inhibiting AKT/mTOR signaling

Previously, we confirmed the anti-tumor effects of sodium butyrate (NaBu) in nasopharyngeal carcinoma (NPC). However, its molecular mechanisms have not be fully elucidated. In this study, we studied the effects of NaBu on autophagy and explored the relation between NaBu associated autophagy and apoptosis in NPC cells. EGFP-LC3 plasmids were introduced into NPC cells to observed the effects of NaBu on autophagy flux with or without chloroquine (CQ) addition. Autophagy markers were also detected by Western blot. Under NaBu treatment, autophagy and apoptosis markers were detected simultaneously at different time. Then, to explore the roles of autophagy in NaBu induced apoptosis, the effects of autophagy inhibition, via specific inhibitor treatment or key gene knockdown, were analyzed. At last, the upstream signaling and its roles in NaBu induced autophagy and apoptosis were also analyzed. Increased LC3 dots and LC3-II accumulation indicated that NaBu can promote autophagy flux in NPC cells. LC3-II accumulation was earlier than cleaved PARP increment suggesting autophagy activation is prior to apoptosis activation, which was validated by flow cytometry mediated apoptosis analysis. Moreover, autophagy inhibition, achieved by 3-MA treatment or BECN1 knockdown, can antagonize NaBu induced apoptosis reflecting by re-deregulated cPARP and apoptotic rates. Furthermore, NaBu treatment inhibited the AKT/mTOR axis indicated by deregulated p-AKT(S473) and p-mTOR(S2448) and ectopic AKT expression both suppressed NaBu induced autophagy and apoptosis. At last, Western blot showed that HDAC6 dependent EGFR deregulation may account for the NaBu associated AKT/mTOR inhibition. NaBu can induce autophagic apoptosis via suppressing AKT/mTOR axis in NPC cells. Our results suggest that combination of autophagy inhibitors and deacetylase inhibitors may not be recommended in NPC clinical treatment.

mTOR Signaling in Cancer and mTOR Inhibitors in Solid Tumor Targeting Therapy

The mammalian or mechanistic target of rapamycin (mTOR) pathway plays a crucial role in regulation of cell survival, metabolism, growth and protein synthesis in response to upstream signals in both normal physiological and pathological conditions, especially in cancer. Aberrant mTOR signaling resulting from genetic alterations from different levels of the signal cascade is commonly observed in various types of cancers. Upon hyperactivation, mTOR signaling promotes cell proliferation and metabolism that contribute to tumor initiation and progression. In addition, mTOR also negatively regulates autophagy via different ways. We discuss mTOR signaling and its key upstream and downstream factors, the specific genetic changes in the mTOR pathway and the inhibitors of mTOR applied as therapeutic strategies in eight solid tumors. Although monotherapy and combination therapy with mTOR inhibitors have been extensively applied in preclinical and clinical trials in various cancer types, innovative therapies with better efficacy and less drug resistance are still in great need, and new biomarkers and deep sequencing technologies will facilitate these mTOR targeting drugs benefit the cancer patients in personalized therapy.